Crozer Chester Keystone Hospital Billing

I have a bone density test done for the past 3 years. I was paying on my copayment every month. I just received a letter from a collection agency from Boston. This around the 4th time I received it from this collection. I kept paying on my bill every month. I called Crozer billing department and the it I talked to was either just totally stupid, which I had to repeat the account number 3 times. He sounded like he was a stoner or just totally stupid. I also want to know why Crozer doesn't keep billing records on their patients. I had this same collection company that threaten to sue me which is totally illegal. They can not legally threaten you with a lawsuit. I called Crozer and they said my bill was paid off. I also received a letter from Crozer that the bill was paid off. I am so swamped with paperwork due to my husband's medical records. I was cleaning my desk out and destroyed some of the paperwork. I must have destroyed the letter I received from Crozer. Now if you tell someone that the hospital bill is paid off and then receive a letter from a collection agency, and then call billing and told I can't tell you anything about that. That tells me, never to use that hospital ever again. They can take me off their list. I will never use that hospital ever again.