Bonitas refuse to pay my hospital bill as agree on

Bonitas send me the cost that they will pay for my wife operation on her ankle, but after the operation was done bonitas reduce the amount that they have send to me to pay with more than R3500.00. They now inform me the following reasons:<br> 1) The doctor i have use is not a approve Doctor of Bonitas<br> 2) The hospital is also not a approve Bonitas hospital<br> 3) the last reason is that they can pay any amount that they wish. because that is why they did write on the letter (cost break down letter) send to at the bottom that this letter do not guarantee for payment.<br> Bonitas told me if i know that the doctor was over charging me, and that is than also one of their reason why they did reduce the payment from their side.<br> Bonitas did know how the doctor and the hospital was when they did send me the cost brake down.