owed R3000 due to claim mistakes

I initially submitted a claim and a mistake was made and I was not paid out the full amount. I enquirered and was told that there has been a mistake and I should wait for my statement for the following month and resubmit the claim. Because I go to this service provider weekly the amount had increased. I paid the practitioner an amount of 4500 which is what was owed and re submitted the statement with my proof of payment attached. I have only been reimbursed an amount of 1500 because according to you the previous service dates were already reimbursed however due to the first error they were not reimbursed but carried over to the next months statement which I paid and then resubmitted. This is very inconvenient as I am owed and additional R3000, which is available in my medical savings but I can't access it due to a number of errors on your side.