Contract bi-Standards

My mother got a Cell C contract back in 2009 and she was the primary holder of the contract and bank account, when I finally got a job I called Cell C to change the contract to my name but I was told I can't make changes to the contract as I'm not the primary holder. Then I called again and asked them to change the bank accounts to my account at Absa and they didn't have a problem with changing that even though I'm not the primary account holder. On upgrading in 2013, we asked in the shop that the contract be changed but we were told to send an email to their contracts department and will be changed. It has since never been changed, and now I need to upgrade but I can't because I need my mother to actually call them. I am amazed that when it comes to money matters then don't have a problem changing the details without emails nor primary contract holder but when I need to upgrade or change details, I need my mother.