I have since solved my problem, yay!
The problem is this line in my service contract:
[OperationContract(Name=”SynapseRequestProcessor”, Action=”ProcessSynapseRequest”, IsOneWay=false, ReplyAction=”*”)]
ReplyAction cannot be set to “*” otherwise no operations or type information are generated in the WSDL when you go to http://localhost/Service/?wsdl
Not sure why this is the case, would be nice to know if anyone knows why?