Something similar happened to me but it was the pin which locates the seat catch and acts as the hinge for the catch. The pin had moved over to one side and slipped out of it's housing, this seemed as if it had broken off but in reality all it needed was for the pin to be pushed back into the centre of the catch and the whole catch located back into the housing by first inserting the inner side of the pin and then pushing the catch inwards until the outer part of the pin located. hope this confusing text is some help
