Discovery can allow you to have a operation and then decline to cover you after op!

I went for an operation for a hernia in December 2019, They gave me an authorization number and proceeded to allow me as a client to have surgery. Only to 7 days later cancel my claim and reject the authorization number. Now I owe Olivedale clinic and Discovery huge bills exceeding over R20 000, Discovery has cancelled my membership. Disgusting to say the least.