Appy for a contract

I have a data sim. Whitch i pay via mtn app in store they are always off line absa there is to many ques. The app takes to weeks to reflect I tried to take out a contract on saterday and it was declient due to late payments..... i think this is really bad from them that i have to pay the price for there system or who ever workes on that. I tried for the bussiness plan 6.5 gig data and 200 min but in store they said i dont own a bussiness so i cant apply for it.... is my money not good enouth