Cancellation of upgrade

I wished to cancel an upgrade I did at a Cell C store the following day. Between the store and Cell C i am.not able to find anybody that can assist and is being sent from one department to another without anyone able to assist. Nobody knows what to do or cab assist. Seems nobody in this organisation knows what to do and customer care is something they know nothing about. I have been struggling for two weeks between all this departments with zero results.