expired contract

my MTN contract expired on the 28 of april 2015 and they have not cancelled the contract automaticaly and i have been receiving their package. now im busy asking them to cancel the contract and they keep on telling me that its on areas and they are not able to cancel it because of that. yesterday i called in the 808 derpatment and it was a nightmare for me because i talked to 5 different consultant and they were all saying a different story. anohter lady gave me a number to call nd i found that the number is not working and when i called in to verify a male consultant told me that they have technical problems that is why the number is not working. i called in again explainging to them that the number is not working i asked for verification of the number a lady told me that they have no such number. i have an impression that mtn does nto want to cancel my contract because if its not that the account is in areas they tell me that i need to give them a month notice so i wonder how long does a month notice take.