The term "social contract" is metaphorical.  It does not refer to an actual piece of paper which specific parties signed and dated, which can be taken to court and enforced.  A legal contract is all that, for the most part.  It is possible to enforce an oral contract in law, but it is done by analogy to a written contract.  A social contract, in contrast, is not analogous.  It is a way to describe the idea of a committment between government and citizens, or between one group of people and another.  It is a metaphor only, and a judge has no jurisdiction over its enforcement.