After a few hours spent at the emergency room due to a dog bite I ended up with $2000 bill.

My insurance has paid already all but $25 which is my copayment...

I mailed my check on 7/9/03 and it was cashed as I check my balance on line almost every day, but to my surprise today I have gotten another bill for the $25 copayment...

I didnt make a copy after my mailed check adn I was wondering how could I prove to them that my check was cashed already...

Any advice? I am gonna call them tomorow and ask why do they keep billing me after they cashed my check..