MTN Contract cancellation nightmare

MTN is taking my money for no reason ,i had an contract with them for a year it is now 3 years +, their still want me to pay them ,when i said that i don t want to continue with the data and airtime contract ,we agree with you for a year only i called the MTN Service number 135,everyday their keep on hanging up on me after transferring me from Department to Department, I am not working and i have no money to continue pay areas that you charging me every time. ,to make things worse they have blacklisted me...Need Help Please