Disgusting Service

I am baffled at the pathetic service I am receiving from MTN being a new customer that signed a data deal of R199 and to be sent bills of R1399 just 7 days after taking out the package and only using it for 3 days. When I visited the store to have this resolved as it their mess up I get referred to the call centre and have been passed from pillar to post since then with consultants that scream at customers instead of fixing the problem. It has been over a month now and still the billing department cannot fix this mess. Managers don't even have the courtesy to call back and I have to keep following up to get feedback. I am at my wits end, next step Ombudsman.