POOR MTN Service because even when you querry no one attend to the matter,Mtn contract its a ****

After 24months of contract with MTN, my husband went to Mtn store to cancel the contract, they insisted that he must upgrade due to financial strain we couldn't,we called to query he was informed to get a proof of cancelation he went to several store get the contract canceled .@fourways Mtn they told him it was canceled, After its been 6months hes receiving calls from Lawyers saying he owes 1400 to Mtn,how come?***MTN WE ARE POOR PLEASE,,THIS IS A fair# ****