Mtn is running a ****

I have been patient long enough with Mtn. I cancelled my contract this year end of feb after they’ve given me a run around since November last year. I had no devices charges for the cancellation,but somehow out of nowhere I have been billed over R4000,I am unaware of where this charge has come from,Mtn saves contacted me saying that they are going to credit me the money that I have paid from last year November till February but I haven’t been credited,I want that amount to be cancelled out as this is going to tarnish my name! Why is that MTN’s customer service suck so much,for the life of me I beg you people not to sign up with Mtn as you will not be satisfied with their service,I have pulled through statements but I can’t seem to find the credit they promised to fund me with! Now you guys want to tell me my account is in collections for what? I demand answers MTN otherwise I will sue you for all the months I have been paying you ..This is the way you treat me?Would have been better if I did not pay you at all but being the person I am I have been religiously paying every damn month!I cannot believe a Giant like you Mtn can actually ruin a persons name by being so ***********!I am sick and tired of your poor service, your incompetence to calculate properly and the deception , I demand answers where is my credit that you promised me and where did this other other amount come from that I am unaware of ? This is so annoying and I am so frustrated ! CEO (Charles Molapisi) of Mtn is this what your company stands for because you are pushing me far away from you !