Incorrect contract amount

Went to bara mall mtn branch to get my new mtn contract. Then when I got the billing for the first time I was surprised cos normally the first billing is not double the actual contract amount. That's when the first alarm went off. I called 808 and they said they will look into it. Then I waited for them to get back to me and they ddnt so went to maponya mall and was told that the person who dd my initial contract said I wanted 200 SMS's added to my contract, I mean who still uses that many sms's? Anyway they were no help. I called 808 and some guy helps me and things looked promising, I got my refund for being charged extra. I was happy till I got my invoice for feb the ****** sms's are back. I would like mtn to permanently sort this out or I they will cancel their contract coz I can't be charged for something I dont want and not using. They better sort this matter out coz their incompetency is costing me time and money which I don't have both of.