Bad service

3 weeks ago I went into the Mtn shop to block a sim card and get a replacement sim card as it is a contract sim card, I was the told by the consultant that my account showed an arrears amount which was paid and i provided her with the p.o.p two days later. i was then advised that i will have to wait for about 2-3 working days before i could come and collect the replacement sim card. Up until today i have not received the replacement sim card, I visited the mtn shop again on the 28th of July but was advised that the consultant who logged the query was not there and they were unable to provide me with any details pertaining to that query. I was then more then willing to pay my other contract but was advised that if i dont pay for the sim card that i was waiting on my services will ne suspended.I stormed out as i am not willing to pay for a sim card which is not in my possession. And this morning i received a sms saying that i must pay to avoid suspension...but how can i pay for some thing thats in transit some where?