No reasons for declining PMB claim

I have been struggling for more that 6 weeks for Discovery to pay for a PMB ( Prescribed minimum benefit). They just keep responding with “ Your request was declined” and then they are so unhelpful to list why. A wonderfully clear “ We need the following • Diagnosis of prescribed minimum benefit. “ And that according to them should explain why they declined multiple reports diagnosing me with a PMB . Even the theatre report noting the removal and thus confirmation of the diagnosis is not enough for them. And here is the important part. No one can give me a reason why.