Hospital Authorisation System Error

After 5 years of irregular menstruation, my gynae recommended I try the Mirena IUD. I went for the procedure to have it inserted in the Doctor's rooms. Unfortunately I am one of the rare people they mention in the indemnity form and I had a vasovagal attack with a seizure. My Doctor was unable to complete the insertion and advised that it is impossible for it to be done in her rooms as this will happen again. It is extremely dangerous and the only way for the procedure to be done is under General Anesthetic.<br> <br> I sent the letter of motivation I received from her to Discovery to apply for hospital authorisation. They declined it. I understand if they won't cover the device or Doctor as its a contraceptive, but it has to be done in hospital. As my medical aid provider, the hospital should be covered by Discovery. My application was escalated and I received authorisation by email. I went to the hospital and booked the procedure for 15 Feb. <br> <br> I called Discovery to change the date on the auth letter and was advised the auth was sent by the system in error and should have been declined. I have it in writing from Discovery. How can they now go back on a written authorisation?