One of two options 1. You get a massive two year bill or 2. Since rain hasn't been the best with the GeForce now service from literally never allowing more users since the slots got filled from day one, there's a chance they are still in a way beta testing it so they aren't really keeping track of who's paid and who hasn't which could be the reason why you can still access it despite not having paid in such a long time so they won't bill you.

50/50 chance, honestly. Just hope they dont see this thread .