WCF Error "Found multiple X.509 certificates using search criteria"

I receive following error when I try accessing a WCF service hosted on our staging server.

"Found multiple X.509 certificates using the following search criteria: StoreName 'My', StoreLocation 'LocalMachine', FindType 'FindBySubjectName', FindValue 'StagingServer001'. Provide a more specific find value."

I try to access the following URL and get above error:

http://stagingserver001/MyService1.svc

Could anyone please guide me how can I find the certificate in the store to delete it? Or what changes I need in configurations of WCF

Please find below the the relevant code taken from web.config of the WCF service

<behaviors>
      <endpointBehaviors>
        <behavior name="endpointCredentialBehavior">
          <clientCredentials>
            <clientCertificate findValue="SPLEBUSSTG02" storeLocation="LocalMachine" storeName="My" x509FindType="FindBySubjectName" />
            <serviceCertificate>
              <defaultCertificate findValue="772f3fdf2496c9750be3b0713003b47b15dfde96" storeLocation="LocalMachine" storeName="My" x509FindType="FindByThumbprint" />
              <authentication certificateValidationMode="PeerOrChainTrust" />
            </serviceCertificate>
          </clientCredentials>
        </behavior>
      </endpointBehaviors>
      <serviceBehaviors>
        <behavior name="SecurityBehavior">
          <serviceMetadata httpGetEnabled="True"  />
          <serviceDebug includeExceptionDetailInFaults="false" />
          <serviceCredentials>
            <serviceCertificate findValue="772f3fdf2496c9750be3b0713003b47b15dfde96" storeLocation="LocalMachine" storeName="My" x509FindType="FindByThumbprint" />
            <clientCertificate>
              <certificate findValue="SPLEBUSSTG02" storeLocation="LocalMachine" storeName="My" x509FindType="FindBySubjectName" />
              <authentication certificateValidationMode="PeerOrChainTrust" />
            </clientCertificate>
          </serviceCredentials>
        </behavior>
        <behavior>
          <!-- To avoid disclosing metadata information, set the values below to false before deployment -->
          <serviceMetadata httpGetEnabled="false" httpsGetEnabled="false" />
          <!-- To receive exception details in faults for debugging purposes, set the value below to true.  Set to false before deployment to avoid disclosing exception information -->
          <serviceDebug includeExceptionDetailInFaults="false" />
          <ServiceErrorHandler />
        </behavior>
      </serviceBehaviors>

    </behaviors>