In 2008 I paid in full (out of pocket) to have a procedure done. I recently found out from another dentist that that procedure wasn't actually done and that they just medicated my tooth. I return to have them do what I've paid them to do and they tell me that I have to pay additional money b/c a few years have passed and had I returned to my general dentist there they would have told me it wasn't done. I find paying additional for something I've already paid in full to be ridiculous. What can I do?