Poor attitude and worst customer service ever

Appauling customer service from Cell C. Over a year ago we cancelled our debit order at the Alberton branch and have been paying via eft since every month on time. Go to the Mall of South store to upgrade last month advised I could not upgrade due to debit order being returned bearing in mind this was supposed to have been cancelled already over a year ago. Was due for an upgrade yesterday go to Boksburg store. Told is cant upgrade have to wait 3 months because of the same debit order story. I pay between R2500 and R2900 a month on a Cell C bill on time and now u dare to decline me an upgrade which will cost me far less because your pathetic store staff with their terrible attitudes did not do their job in the first place. Not to mention you appauling signal utterly disgusted to other ppl out there avoid Cell C at all costs they the worst service provider by far.