How to read soap response xml in php

try the code below. I am assuming your xml response is in $soapXMLResult variable

$soap     = simplexml_load_string($soapXMLResult);
$response = $soap->children('http://schemas.xmlsoap.org/soap/envelope/')->Body->children()->CreateRebillCustomerResponse;
$customerId = (string) $response->CreateRebillCustomerResult->RebillCustomerID;
echo $customerId;

How I did, create eway soap request and get eway soap result,may help others!

 <?php
    $URL = "https://www.eway.com.au/gateway/rebill/test/manageRebill_test.asmx?wsdl";
                $option = array("trace"=>true);
                $client = new SOAPClient($URL, $option);
                $functions = $client->__getFunctions();
        $headeroptions=array('eWAYCustomerID'=>"87654321",'Username'=>"test@eway.com.au","Password"=>"test123");
                $header = new SOAPHeader('http://www.eway.com.au/gateway/rebill/manageRebill', 'eWAYHeader',$headeroptions);

                $bodyoptions = array(
                                "CreateRebillCustomer" => array(
                                    "customerTitle" => "Mr",                   
                                      "customerFirstName"=>"Muhammad",
                                      "customerLastName"=>"Shahzad",
                                      "customerAddress"=>"cust ome rAddress",
                                      "customerSuburb"=>"customer Suburb",
                                      "customerState"=>"ACT",
                                      "customerCompany"=>"customer Company",
                                      "customerPostCode"=>"2345",
                                      "customerCountry"=>">Australia",
                                      "customerEmail"=>"test@gamil.com",
                                      "customerFax"=>"0298989898",
                                      "customerPhone1"=>"0297979797",
                                      "customerPhone2"=>"0297979797",
                                      "customerRef"=>"Ref123",
                                      "customerJobDesc"=>"customerJobDesc",
                                      "customerComments"=>"customerComments",                    
                                      "customerURL" => "http://www.acme.com.au"
                                   )
                                );

                    try{
                        $response = $client->__soapCall("CreateRebillCustomer", $bodyoptions,NULL,$header,$outputHeader);
                        //echo $client->__getLastRequest();
                        //$response = $client->CreateRebillCustomer($bodyoptions);
                        //echo "<pre>";echo "<br/>";
                       // print_r($response);        
                            echo    $result         = $response->CreateRebillCustomerResult->Result;echo "<br/>";
                            echo    $customerId     = $response->CreateRebillCustomerResult->RebillCustomerID;echo "<br/>";
                            echo "<br/>";
                        if($result=='Success' AND $customerId){
                            echo 'Member Created at eWay Successfully!...<br/>';
                            echo 'Creating Recurring Billing Cycle on eWay,Please wait......<br/>';
                            //$UpdateRebillCustomer = CreateRebillEvent($customerId);
                            //print_r($UpdateRebillCustomer);

                        }
                        else{
                            echo    $ErrorSeverity  = $response->CreateRebillCustomerResult->ErrorSeverity;echo "<br/>";
                            echo    $ErrorDetails   = $response->CreateRebillCustomerResult->ErrorDetails;echo "<br/>";
                        }
                    }
                    catch(SOAPFault $e){
                        print $e;
                    }

                    if($customerId){


                                $bodyoptions2 = array(
                                "CreateRebillEvent " => array(
                                      "RebillCustomerID" => $customerId,                   
                                      "RebillInvRef" => "Ref123",
                                      "RebillInvDes"=>"description",
                                      "RebillCCName"=>"Mr Andy Person",
                                      "RebillCCNumber"=>"4444333322221111",
                                      "RebillCCExpMonth"=>"12",
                                      "RebillCCExpYear"=>"15",
                                      "RebillInitAmt"=>"100",
                                      "RebillInitDate"=>date('d/m/Y'),
                                      "RebillRecurAmt"=>"200",
                                      "RebillStartDate"=>date('d/m/Y'),
                                      "RebillInterval"=>"31",
                                      "RebillIntervalType"=>"1",
                                      "RebillEndDate"=>"31/12/2013",                     
                                   )
                                );
                        try{    
                            $response = $client->__soapCall("CreateRebillEvent", $bodyoptions2,NULL,$header,$outputHeader);
                            //echo   $client->__getLastRequest();           
                            //print_r($response);
                            echo "<br/>";
                              echo  $result2        = $response->CreateRebillEventResult->Result;echo "<br/>";
                              echo  $RebillCustomerID   = $response->CreateRebillEventResult->RebillCustomerID;echo "<br/>";
                            if($result2=='Success'){
                                echo 'Recurring Cycle Created Successfully at eWay!...<br/>';
                                echo 'Member Id is ===>'.$RebillCustomerID;
                                //$UpdateRebillCustomer = CreateRebillEvent($customerId);
                                //print_r($UpdateRebillCustomer);                           
                            }
                            else{
                                echo    $ErrorSeverity  = $response->CreateRebillEventResult->ErrorSeverity;echo "<br/>";
                                echo    $ErrorDetails   = $response->CreateRebillEventResult->ErrorDetails;echo "<br/>";
                            }

                        }
                     catch(SOAPFault $e){
                        print $e;
                     }

                     }

                  ?>