In USA I wonder how they forced you to enter contract with medical provider. A letter to debt collector to 'validate alleged debt and show me the signed contract' could be interesting.
I did that exact thing and they sent back a rejection of the dispute along with shitty screenshot of me listed as "guarantor" of ICE's health service corps lol. Obviously I refused to sign anything. I have no idea how the collectors even found me as I had no valid contact information as the feds put their own address as mine.
FDCPA has provisions for a letter with specific words to make them stop contacting you. They will likely ignore that, so consider if you would then sue for damages.
Most States have a 'declaratory judgment' law in which an issue is brought to court and decided. You could force them to prove a contract in a court. They will probably not show up. Or they could show up and you could get corrupt judge and lose.
