Hi, the actual endpoint doesn't have a "?WSDL" at the end. The find the actual real endpoint location (and perhaps correct wsdl as well), log into enterprise manager (typically http://ipaddress:7001/em), then browse SOA >> soa-infra >> your_partition, right click on your composite and choose the endpoint in the "test service" option. On the test page you will see the "Endpoint URL" text box - you can copy it from there and give that to them as the actual endpoint. The real correct wsdl is also in the "WSDL" text box at the top, it also contains the actual endpoint for the service.
For exposing an https composite service there is already a forum discussion on this topic here: Re: How to make secure(https) SOA composite over network?