Cell c taking my money for wasting my time

We took out a cell c data deal for 80gig. Just to discover that we don't have network coverage as they assured us. They did a network investigation and confirm that we have no cover and the contract should be canceled. We returned the device for cancelation before 25July. We paid an activation fee, pro rata fee plus R500 for August even though the device was already with cell c repairs and they were to slow to cancel the damn contract in time! Costing me R500 for August. I lost R1200 for trusting cell c and never even using the contract! Poor service and they won't repay the money even though they sold me the wrong contract! What a waste of time and money