Unable to upgrade

I have been a customer of Vodacom for over 6 years now. This past month my account was migrated to a 'new system'. Since then my account has been double charges, the account is showing that money is overdue and I am unable to upgrade even though the system states I can upgrade since 3 months ago. I have spend time in the actual store where they could not assist due to incorrect details on the system. I have also tried via the call system which I was referred to and was only told again that only the stores can help. This is poor service as clearly everyone can see the fault on the system but they are just passing the buck to someone else.