Aspen Dental Charged 4X more for basic fillings than the signed, agreed upon price, after the fact. Medford Massachusetts

I went to Aspen Dental in Medford, MA to get a cleaning and a few cavities filled. After my initial consultation, I was given an estimate for what the fillings would cost. The price was about $275 for all the work, and they informed me they accept my insurance. I signed the paper and paid in full, upfront. 

After two more visits to get all my cavities filled, I thought I was all set as I paid the full amount of the agreed upon price. One month later I recieved a bill for over $850. I was outraged! How could they charge me 4x the amount that they originally told me it would be? 

Aspen Dental has a motto which is, "Peace of mind promise." and they go on to say that you will never get charged for any suprise fees. Well they did the exact opposite in this case. They told me a price, I paid it, then they charged me 4x the ammount after the fact. If I had known it would have been almost $1,000 to fill some cavaties, I never would have done it.

I called them up for months, and at one point even had a service rep tell me they would clear my balance because I did indeed pay what was estimated. That did not end up happening as they have turned my bill over to debt collectors who have been hasseling me for months now.