Discovery not covering PMB condition

I contacted Discovery to authorise a transaction - I was told that there would be a deductible, unless the doctor sent a letter indicating a PMB condition. I contacted the doctor and they sent through a letter confirming the condition, which I sent through to Discovery. In spite of the fact that Discovery stated they would come back to me regarding the issue within 2-3 days, I got no feedback. When I phoned a week later, I was told that because the doctor didn't state in the letter than Discovery should waive the deductible, the letter was ignored. I then contact the doctor to change the letter to state that it is a PMB condition and that Discovery should thus waive the deductible. When I phoned today, I was told that because the letter wasn't a "confirmation of diagnosis" the letter was again ignored (in spite of the letter stating that the patient had a PMB condition).

Every time I speak to Discovery, they have a different excuse for ignoring the information that they required. Discovery obviously doesn't want to cover PMB conditions.