Coast dental over charge, Getting a bridge put in and now after 8 months want to expand. Winter springs Florida

In January went in with broke front tooth, Decided to do bridge. Scheduled apt, Went in and did impressions and bone work to prep. Went in 1 week  later had temp implant put in. Covid came. Went back in june to find out that the doc that started is no longer there. New dentist immediately did not like what was previously done. Tried to put in permanent bridge and did not fit or look even close. Doc and I decided not to install and ask for retake. meanwhile new temp installed ,1 day later temp fell out . went in 1 week later new temp . Fell out same day .

Tried calling to get sorted out and could not reach anyone in corporate. So i drove to tampa. Worked out a consult with new doc and thought we were moving forward and they referred me to new dentist for consult for what they started and would not pay.I decided not to go since it was completley out of pocket. They offered a partial refund. After that now they want to enlarge the bridge to 4 teeth and want me to pay more money. My insurance has paid in full and I paid 1800 out of pocket. They will not refund 100 percent. I have contacted the better business and tried calling them multiple times and no one will return my call.