Aspen Dental review: Dental estimated charges vs actual charges

Aspen provided me with an estimate of charges to do dental work on me. They took my insurance card and told me that insurance would provide discounts of $7,445.01 and that the insurance would pay $2,863.92. They said my financial responsibility would be $5,765.07. They began doing the work but before beginning work they billed me and I had to pay them. Every time I went for more work, I had to pay up front. Meanwhile my insurance wasn't sending any information related to EOBs. I inquired with the billing person and they said the insurance company was likely understaffed and running behind and not to worry about it. I began receiving bills from Aspen that didn't make sense as they didn't match the estimate provided by them. I called the billing person on three separate occasions and had to leave messages. They never returned my calls. Meanwhile I still had dental work that had to be done. Long story short, I went for my most recent appointment and they said I owed them $1047 and had to pay before the work could be done. I left. I have paid them $10,134.48 but they told me I would owe $5,765.07. As such I believe they owe me a refund of $4369.42. I am prepared to take this to the State Attorney General for violation of the consumer protection laws of the State of SC. Any assistance you can provide prior to my doing this would be greatly appreciated.