MTN is the worst

MTN is the worst network provider . They have the worst customer service . They have taken money from my account even though I have cancelled my contract in December . They are promising manager call backs but fail to call. The contract finished but yet in January they took a instalment which was incorrect because i was told that my last instalment was in December by an advisor . I am now out of pocket for the amount they have taken . Poor service and they are not refunding my money .