Dealer cant reproduce issue; now what?

superbase

So I had the dreaded CSC failure where the clutch stuck to the floor. Dealer obviously couldnt reproduce it on the spot so all they did was replace the fluid. If they cant replace it but I know the problem exists, is there anything I can do? I tried telling them that it's a safety issue which of course they laughed at since "you can just coast to a stop". I countered saying any loss of control input with the vehicle is a safety issue, what if I cant move out of the way because I'm stuck on an old country road at night with low visibility and no shoulder? Someone could rear-end me. They just said "we cant replace it if we cant verify it exists".

Great, so until my car full blown breaks down on the highway requiring a tow they wont do squat. Or will they? Is there any way to force their hand? Should I just bring my car in every day claiming the peddle stuck till I annoy them to death? Threaten to talk about the issue with customers while they examine my car? Advice?