<prompt> Human: I received a call today from a debt collector who claims I owe them 42 from a 35 doctors co-pay in 2013. They were nice enough at first, and I was polite. When I asked them to send me a bill, the lady got aggressive and nasty. I was able to bite my tongue and requested a bill a couple more times to no avail. She straight up said she wouldnt send me one and that if I wanted to verify it, I need to do the foot work whatever that means.Any advice? Maybe I do owe them 42 but I would like proof that I do and proof that I pay it off, if it is valid. Assistant: Shrug. Hang up. Tell them to quit calling.Human: If its valid, I want to take care of it.  <response>: Someone who wants you send money but wont provide the reason why is a scammer and nothing more. 