How to send request to soap webservice in ios?

hi i want to send request to the soap webservice. I tried in AFnetworking and getting internal server error 500 and now iam trying in nsurlconnection but it also showing status code 400. Please any one help me. Thank you Advance hear is My code.

NSString *soapString = [NSString stringWithFormat:
                                    @"<?xml version=\"1.0\" encoding=\"utf-8\"?><soap12:Envelope xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\" xmlns:soap12=\"http://www.w3.org/2003/05/soap-envelope\"><soap12:Body><addBusOrder xmlns=\"http://tempuri.org/\"><UserUniqueID>ok//8FjcvEKWMeeJJZHKYA</UserUniqueID><PlatFormID>4</PlatFormID><DeviceID>E3D2FCF6-F41B-4275-BD34-FAA31307EFFE</DeviceID><RouteScheduleId>532875503</RouteScheduleId><JourneyDate>2016-03-25</JourneyDate><FromCityid>734</FromCityid><ToCityid>202</ToCityid><TyPickUpID>22860424</TyPickUpID><Contactinfo><Name>vinod</Name><Email>katragadda.vinod@gmail.com</Email><Phoneno>7842768497</Phoneno><mobile>8801720427</mobile></Contactinfo><pass><passenger><passengerName>kumar</passengerName><Age>23</Age><Fare>1072</Fare><Gender>M</Gender><Seatno>D3</Seatno></passenger></pass></addBusOrder></soap:Body></soap:Envelope></addBusOrder></soap12:Body></soap12:Envelope>"];
            NSLog(@"soapString %@",soapString);

    NSString *msgLength = [NSString stringWithFormat:@"%li", [soapString length]];

    NSString *queryString = [NSString stringWithFormat: @"https://asprel.in/Service/AppServices.asmx/addBusOrder"];

    NSURL *url = [NSURL URLWithString:queryString];

    NSMutableURLRequest *req = [NSMutableURLRequest requestWithURL:url];

    [req addValue:@"application/soap+xml; charset=utf-8" forHTTPHeaderField:@"Content-Type"];
    [req addValue:msgLength forHTTPHeaderField:@"Content-Length"];
    [req addValue:@"http://tempuri.org/addBusOrder" forHTTPHeaderField:@"SOAPAction"];
    [req setHTTPMethod:@"POST"];
    [req setHTTPBody: [soapString dataUsingEncoding:NSUTF8StringEncoding]];


    NSOperationQueue *queue = [[NSOperationQueue alloc]init];
    [NSURLConnection sendAsynchronousRequest:req queue:queue completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {
        if (connectionError) {
            NSLog(@"error %@",connectionError);
        }else{
            NSLog(@"data %@",[[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding]);
        }


        NSXMLParser *parser = [[NSXMLParser alloc]initWithData:data];
        [parser parse];

    }];
}

Error:

status code: 500, headers {
    "Access-Control-Allow-Origin" = "*";
    "Cache-Control" = private;
    "Content-Length" = 322;
    "Content-Type" = "text/plain; charset=utf-8";
    Date = "Thu, 24 Mar 2016 07:08:32 GMT";
    Etag = "\"\"";
    Server = "Microsoft-IIS/8.0";
    "X-AspNet-Version" = "4.0.30319";