Quote and Invoice

My problem is with the accounts department and not with the Doctor or Nurse. I phone the department to get a quote for a procedure they quoted me R2800.00. so I made an appointment to have it done. When I got there the lady in reception done the booking and told her I will pay so as not to exhaust my Medical Aid Saving. I got the invoice for R2800.00 which I paid. Then a few days later I got an Invoice for R3056.30 So I emailed the to complain, I said to the lady that I was quoted R2800 which I paid, and said that they must have done plenty of this Procedure so you should be able to give a more accurate quotes. She said she would come back to me. But never did they went through the back door and submitted to the Medical Aid which I got an email to say the Claim has been processed, I have contacted my Medical Aid to reverse this claim, then they will have to contact me.