Orthodontist changed the price of my care after one year in braces and took them off because I couldn't pay.?

My initial visit to the Orthodontist was to see how much it would cost to straighten my four lower front teeth. The rest of my teeth were very straight. The Orthodontist agreed that my teeth were not bad and said "you will only need braces for about a year and that will be much cheaper for you". So they gave me the estimate of $1100.00. My insurance said they pay 75% up to $2000.00. My cost would be $375.00 ($275.00 plus my $100.00 deductible.) I agreed to the service and the braces were put on in October of 2009. All through the treatment the Orthodontist was telling me my teeth were moving good, and she started talking about them coming off around July 2010. Then one day after my adjustment at the end of August 2010, the appointment person told me there had been a mistake when they priced my braces and that I owed them $1700.00 to be paid before they could remove the braces. I freaked out, I could not pay $1700.00, no way. Then I found out that they already billed and received the full $2000.00 from my insurance. After them refusing to touch my teeth for four months the said they would take them off, this was January 2011, but that I had to buy the retainer that cost $500.00 or my teeth would shift back. I did buy the retainer and figured everything would be alright, but I had some bite issues and the Otho assistant said "that's because your bite was not finished, WHAT? So now my mouth is worse than when I started I am biting my tongue all the time and if I speak more that one sentence I start to sound like I'm drunk. This has to be corrected, please tell me where to start. Thank you. Sharon Behnke