Worst service provider ever

I would just like to take this opportunity to tell everyone about the terrible service I have been receiving from Cell C these past couple of months. Firstly they updated my debit order date , however they only changed 2 of the 3 contracts debit order dates, this apparently makes sense to do. They then did not update the banking details on all three my contracts so the one debit order kept going off on the wrong account, I usually EFT the payment prior to the debit order date, so I didn't notice it until later. On both these occasions they said it was my fault not theirs or I had to go to the store and fix it due to Cell C staff being ***********. The last matter they did that just ticked me off, I was phoned last week to tell me I am eligible for an upgrade, however the upgrade cannot be done because the person at Cell C that updated my debit order dates, did not update all 3, meaning on "the system" my payment was late, and my record is bad due to that, but I did give them the months notice. The consultant that phoned me Saturday (15 June 2019) said that she would phone me back and assist me to fix the matter. I was never phoned back. Thank you Cell C for 6 years of bad service.