Incorrect Billing

I app**** for 2 additional cell phone contracts in July 2015 as was advertised by Mtn in their May/June brochure. I asked that the contract be as is advertised for R349.00 p.m top up. This was however NOT done. On 1 contract a R0.00 limit was set and the other 1 was left as unlimited. This resulted in an exorbitant bill which I have been debited with. I have been trying to resolve this matter since 9 Feb '16 and was advised that it would take 24-72hrs for a reply. I heard nothing from them until today(17 Feb '16) when I called to follow up for the 3rd time. I was conveniently advised that it was my problem as I was supposed to soft lock (whatever that is) becos mtn corporate sales does not set limits. I find this totally unacceptable as I asked for what was advertised as is and the contract is certainly captured at sales, furthermore why would 1 phone number have a R0.00 limit and the other is unlimited when both were ordered at the SAME TIME!!! This has left me out of pocket to the value of almost R30 000.00 as my account has been dr with no less than R8000,00 - R 10 000.00 each month since Sept '15. I cannot accept the explanation provided by their Administrator (Avhashoni).