Positive Covid tests not paid

Referred for Covid testing by a doctor contracted to a state hospital in July 2021. The tests came back positive. Discovery rejected the invoices from Lancet as there was no practice number on the invoice. Lancet was then requested to insert the practice number that reflected on the referral letter. Takes lancet months to get this done. Discovery then rejects the practice number as it belongs to a state hospital. No amount of explaining that the doctor was contracted and working for the hospital would satisfy them. We were advised that since the doctor had subsequently left the employment of the hospital and had his own practice we were to ask Lancet to have the current practice number inserted on the invoices. Lancet supplies us new invoices. Discovery open up the file again (as it is from a prior year), and then reject the invoices as the practice number is newer than that date on the invoices. We have refused to pay Lancet as the cost of the tests would come out of OUR medical savings which were not depleted in 2021. We have advised Lancet we will defend any summons, which has been threatened by their attorneys, and will make an application for Discovery Health to be added by a Joinder application when we defend the matter in court. Funny how our medicine for treating the Covid infection was paid from OUR medical savings using a prescription with the same practice number, however the tests that confirmed the infection are rejected.