Could a breeder claim for unlimited rights to use our dog as a "reproductor"

We bought a dog thinking the contract give it to the Seller rights for 2 stud services as core of the contract states for dogs in a Full Registration program. We thought we were at such program, expecting to have AKC papers after second stud service. But at the time of the second stud service -and the last one in our understanding- the Seller said he has unlimited rights to use our dog for stud services since he put at the bottom of the agreement an extra point saying that we allow him to "use the French Bulldog mal for breeding purposes whenever he desires" ... again we thought this was talking abut the 2 services not service for life or something like that ... now he counteroffer 6 times but defining times as studs services that positively ends into female dog gravity ... so what to do?