Customer centricity non existant

I am livid. I have been a Cell C client for awhile. I have a cell phone, three tablets and one computer contract. I called into the store to upgrade the cell phone contract which is due for an upgrade. My son uses the phone. We couldn't upgrade as we could only do so around 17/4/2015 I mentioned to the gentleman I dealt with that although I am the account holder, I am also an hourly paid contract worker and therefore loose money having to take time off work. I asked if my son could do the upgrade without me. He asked me to sign a letter and said it could be done. My son needed his ID and mine. When my son went in to the store on Friday. He was told he cant upgrade because my credit score in 0 and needs to be updated and I need to be in store to do so. I now have to take more time off work and again, loose an income as this cannot be done during weekends. I am bitterly disappointed in the lack on client centricity and inconvenienced caused. My payments have always been made to Cell C via debit order. I don't understand the credit rating score one bit. Should I be leaving Cell C and going to your competitors? Kindly contact me, if you care to keep a client.