Great Doctors - Great Service but Worst and pathet...

Great Doctors - Great Service but Worst and pathetic billing and accounting system. it looks like they want to grab as much money they can from you and insurance. i had an experience recently where they tried to double charge me and then charge insurance as well, it took me a long time to explain that they are wrong...
to detail it out:
They charged me some 990$ before my visit saying, if Insurance doesn't pay then we use this amount as base from you, i said okay and i paid that. Later, after few months i received a letter saying i owe them money, we tried to explain that we already paid money now you need to get it from my insurance, they wont listen to us and handed our case to collection agent. I then called my insurance company and asked them to look into it, what we found out was - they charged me 990 some on first day and then charged insurance for some good amount and then they completely removed my initial payment from transaction history and were trying to acquire more money. Insurance and hospital finally looked into it and now are planning to refund me 200 because i paid more. It took me months to explain that they are wrong. i had to face collection agents, we were embarrassed to put at this spot, i was really depressed on thinking how will i pay 1000$ more after i paid initially.