I'm sick and tired of calling 808

My contract ended on the 11th of August and Mlungisi Meyiwa called me and offered me a new package and I've been calling MTN 808 since the 4th of September trying to cancel the contract / upgrade and no one can assist . They gave me a number for retentions and i called them and they said they will get back to me within 3 days and it's been a month now and i'm still waiting for that call . All I want to do is to cancel the contract . That's it . CAncel the contract and and upgrade and i want to be on prepaid . Who do i need to speak to in order to do that . I dont even know how many times i called 808 and they always tell me the same thing that they will send an email to retentions and retentions never gets back to me . Maybe you want me to take the legal route . I dont want want the contract . Somebody please help me .