Discovery Primary Care/Flexicare not providing agreed refund

I had to see a specialist in March of this year and received authorisation from Discovery Primary Care as I was instructed. The specialist then referred me to a medical technologist for tests. Before seeing the technologist, I phoned Primary Care to confirm whether or not this would be covered. I was assured that as long as the specialist had referred me to the technologist and I used the same authorisation number, it would be covered. I went for the test and was told that it was not paid for, so I had to fork out R800 odd out of pocket, which I hadn't budgeted for. I contacted Primary Care and was asked to submit the receipt and my banking details in order to process a refund. This was on the 14th of April. I have, to date, not received the refund. I have called Primary Care several times and teach time, I'm told that the payment has been approved and paid, yet when I ask for proof of payment, as I have not received it, I'm always told "It will be escalated to the finance department and they will send it to you." Nearly two months later, and I haven't received anything except empty promises.