How to get the list of customers with web service?

Hello everyone,

I'm working in a web application that needs to get the list of customers from c4c, I'm trying to test the service querycustomerin1 passing the bellow request by SOAPUI:

<soap:Envelope xmlns:soap="http://www.w3.org/2003/05/soap-envelope" xmlns:glob="http://sap.com/xi/SAPGlobal20/Global">   <soap:Header/>   <soap:Body>      <glob:CustomerByCommunicationDataQuery_sync>         <!--Optional:-->         <CustomerSelectionByCommunicationData>                        <!--Zero or more repetitions:-->            <SelectionByInternalID>               <!--Optional:-->               <InclusionExclusionCode>I</InclusionExclusionCode>               <!--Optional:-->               <IntervalBoundaryTypeCode>1</IntervalBoundaryTypeCode>               <!--Optional:-->               <LowerBoundaryInternalID>*</LowerBoundaryInternalID>                          </SelectionByInternalID>                  </glob:CustomerByCommunicationDataQuery_sync>   </soap:Body></soap:Envelope>

However the response always is

Fri Apr 01 09:24:07 BRT 2016:DEBUG:Receiving response: HTTP/1.1 500 Internal Server Error.

I'm really stuck here, please help me.