I asked the hospital for a quote, upfront, before the a procedure that my insurance wouldn''t cover. Now the hospital is asking for more money!

I needed an endoscopy done, and I knew my insurance wouldn''t cover the charges due to a pre-existing condition. Long before the procedure was to happen, I explicitly asked for a quote upfront. A long time passed before I started hounding the hospital for that quote, or I would miss my procedure. After finally getting a quote for $2,500.00. I decided to continue with the procedure and paid the amount, in full, upfront. Now, I''m being billed by the hospital for charges stemming from this procedure that should have been included in the original quote. There were no "added" services rendered. All of this money is coming out of pocket. I''m not wealthy by any means. Do I have the right to dispute these charges?