Unethical

Dr Patel was in network I went to another dr before him so I knew my procedure was a covered one. I told both doctor and his OM this. They said to just pay for my procedure and after they would give me the paper work to file and after the check came in dr would give it to me. I had surgery and they would not give me the paperwork. My insurance demanded they file and said 8,500 was covered in full 100%. 5 months after my insurance has been working On this claim dr Patel is now claiming I signed something waving my rights to use insurance. I need proof of that and what was that in the middle of my surgery risk paper work? Shady! I was honest and let them know ahead about my insurance. Both his front desk , om, and himself said they would accept my insurance they even took my card and made a copy! He played me for a fool. I even have emails and paperwork to prove he knew I was filing with insurance. Now instead of insurance I have to go another route. Why lie to your patients?