Reneging on assurances made.

I called in for authorisation for minor surgery. During the call I confirmed that all accounts including pathology will be covered. I was assured that if it pertained to the surgery, it will be covered. no surprises, it was not. I followed up with Discovery, and emailed through a letter from the doctor together with the pathology bill. But I have not received any feedback as yet. The bill is still outstanding. This should be covered by the medical aid. I mean what do we pay for then?