BAD SERVICE FROM MTN

MTN is not doing me any justice, I ordered a phone contract with them, the phone was returned the very following day to MTN at East Rand Mall, there was an electrical issue but my details and copy of ID were taken and I was assured that I will revive a reference number. Up to today I haven't received anything and MTN started debiting from my account for the contract that I don't have, I sent an email to explain the situation and they said they will follow up, now I received an email saying that I should pay or else it will affect my ratings , whose fault is it that some people cant do their job properly?