Need help regard contract with mtn

<p>I signed upgrade contract with Nashua mobile on MTN on 14 /March /14 and my problem was the first month they gave me airtime that I went in store complain abt it they said I have two accounts and I cancelled the other account same time they promise me they gave me paper sign n two months later I was surprised nothing heard from MTN , went to store again they promise they working on matter Everytime I go to mtn outlet till this day they still try fix matter n they took my account to Shapiro Schaumburg debt collector n I tell them MTN still busy with this matter they for e me pay cuz I stopped paying them after 18 months of seeing no progress from mtn</p>