Brighter Dental Care

My son's filling fell out after a couple of months. When he went to a different dentist to have it repaired, the new dentist said it didn't look like there had been any decay and he probably didn't need a filling in the first place. Brighter dental also told him he had four other cavities that would need to be filled. Upon examination by the new dentist, he told him he had no cavities. You must pay in either cash or debit card on the spot at Bright. So after each visit that I or my son had, I paid. Months later I get a bill for over $600. Some of the charges were already paid in cash. I've tried calling several times to straighten it out and get put on hold for 15 or 20 minutes and then get disconnected. Never going back.