Bonitas wont pay a claim after I received confirmation of pre-authorization for it.

I have received an approved authorization on 16/04/2024 for a CT scan. The CT scan was done after I received approval - I needed to first be reassured that it will be covered by the medical aid before going for the scan. Now Bonitas wont pay for the scan and their reasoning is that I need pre authorization (which I have received via email). The radiologists keeps sending me reminders to settle the account. I know that I do have this benefit in place and I have proof of receiving pre authorization so I do not understand what the problem is here. I think Bonitas is just ********* and is looking for reasons not to pay claims.