Service Purchase Requisition not referencing the Contract Correctly

I'm trying to create a Service Purchase requisition through ME51N and I have created Service Contract for the Same service item. When I try to Assign the contract Going through "Source Of Supply" Tab and selecting "Assign Source Of supply" all the details are getting picked as per the Contract except the Price which is Agreed for that service item in the Contract. When I try to do the same for a Material Related Purchase requisition even the PRice is getting Picked Correctly. Please assist me on this whether there is a way to get the contract prices to the service Purchase Requisition.