How to create a web service to recieve request and respond

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C#

XML

webservice

Hello Tech Giants
I need to create a web service either that will implement the following
1. The communication mode is HTTP POST (not SOAP).
2. The content type is text/xml.
3. The POST request will contain only XML and response will be also XML.
4. The request will be a RAW POST directly to stream and NOT in a parameter.
5. It will be a SINGLE URL

I already worked on it here
http://www.nepamsonline.com/PHEDCWebService/PHEDCWebService.asmx
but this is SOAP.
I want it to be HTTP POST.
How do I accomplish this

Thanks

EXAMPLE REQUEST:

<customerinformationrequest>
<routeid>HTTPSERVICE</routeid>
<merchantreference>4781</merchantreference>
<custreference>5294520</custreference>
<serviceurl> https://www.nepamsonline.com/PHEDWebservice/PHEDWebservice.asmx</serviceurl>
<serviceusername />
<servicepassword />
<ftpurl />
<ftpusername />
<ftppassword />
</customerinformationrequest>

EXAMPLE RESPONSE:

 <customerinformationresponse>
   <merchantreference>4781</merchantreference>
   <customers>
      <customer>
         <status>0</status>
         <custreference>5294520</custreference>
         <firstname>pelumi</firstname>
         <lastname>amao</lastname>
         <othername />
         <email>tomiground@hotmail.com</email>
         <phone>08066953623</phone>
         <amount>51000.00</amount>
         <thirdpartycode />
      </customer>
   </customers>
</customerinformationresponse>