Will not refund claim paid

My wife is on the Ingwe option and went to a doctor on 14 Feb 2015 that was approved on the Ingwe plan. We had our medical card however due to load shedding, the doctor was unable to process the medical aid card and requested payment from ourselves( We assume that this is because it was out first visit to the doctor). The doctor instructed my wife that we had to pay in cash due to load shedding and then we must put in a claim with Momentum. We submitted the doctors invoice to Momentum by the 18th of Feb 2014 and still have not been refunded. After numerous calls and follow ups with Momentum, there appears to be a dispute between the doctor and the medical aid wrt a charge code on the invoice. The invoice is valid and we have paid in good faith however Momentum are unwilling to make payment. My wife was told to write off this R400, This is unacceptable and if there is an issue between Momentum and the doctor this needs to be resolved by Momentum and the member should get there claim back. This was only paid because of load shedding.