Looking for ANY reason not to pay????

I have been an active member of Discovery Health since April 2008. I also have life insurance and my retirement annuity supported by them as well. In November 2019 my partner joined as a dependent on my Medical Aid and he also banks with Discovery Bank. When asked about his history - we noted on the application form the major issues or items that came up (i.e. he had major dental procedures in the past) but he still had no waiting periods or exclusions app**** to his application. In January 2020 he complained of pain in his back. He went to the doctor on numerous occasions for treatment including: medication for pain, physiotherapy, dry needling, had x-rays and an MRI. Discovery paid for all of this. When nothing helped with his pain, his GP referred him to a Neurosurgeon who checked the MRI and advised that he needed a disc fusion and replacement to treat this issue.

We app**** for hospital pre-authorisation and that was when the agony really started! Discovery have reviewed his case and declined the authorisation due to non-disclosure of tennis elbow in August 2019. We genuinely and in good faith provided all items that we understood to fall within the collection of previous conditions. Tennis elbow is a type of tendinitis (swelling of the tendons) that causes pain in the elbow and arm. Certain repetitive movements of the wrist can cause this condition. It is also noted that Tennis elbow does not usually lead to serious problems. In fact if the condition had been recurring, we would have mentioned it, however it was a once-off issue and after receiving treatment, the issue was resolved. None of which helps us – because not only have Discovery declined to pay for the only thing that can fix his back issue, they have also cancelled his medical aid membership, and left us with an amount to pay back due to all the previously paid claims. I truly feel like Discovery is looking for an excuse here. The previous item was a once-off injury that has not been an issue again. It does not relate to this new pain or the surgery required to fix it.

Where do I go from here????