Bad and disgusting service by Discovery Health Claims

I submitted a claim at Discovery Health for assessments that were done for my son in February 2018. I paid R6000 cash for these assessments and submitted an invoice received from the practitioners. To date I still have not been reimbursed for it. Firstly the claims department came back stating that the invoice did not have the ICD-10 codes. Then I resent them another invoice highlighting these codes. Then they came back indicating that the practice numbers were not there. I then sent them back the invoice highlighting the practice numbers. Then it was the dates for the assessments and the invoice not corresponding. I then realized that all the information they wanted has been on the original invoice sent to them initially. It has been a back and forth process and I am starting to feel like it's just a strategy not to settle my claim because the practitioner indicated to me that they have always been structuring their invoices like that and that most of the claims went through. I do not understand why mine has been such a cumbersome and long process. I am very disgusted and disappointed at Discovery Health's service because I paid a lot of money for these assessments.