12 weeks still no refund

I canceled my one contract with MNT beginning of May 2015 , for the last 2 months they still continued deducting my account. I called in excess of 8 times already, every time I speak to a advisor the cant help me always \ we have referred the matter to the billing department". Last week I spoke to a advisor and she confirmed the specific amount that should be refunded and that the refund will be done by 16/07/2015.I called this morning to confirm this "