Unable to do Upgrade

On the 01/10/2015 I tried to do a upgrade on this number *** called the upgrade department advise me that they unable to do the upgrade as was on the system shown that I was under debt Review but for the don't know many years with Cell C I am getting this bad service. I tried to explain to the upgrade department why it will show that, my problem is that the contract was never added on my debt review and every month they getting my money and getting debit from my bank account not even 1 payment was returned or not paid since I am with Cell C. Then I was transferred to the legal department and don't let me go there as this will never end all I want to know why was I unable to do the upgrade and the person that was so *********** on my account and when I ask him to speak to the supervisor he tell me I am the supervisor and when I ask him to speak to his manager and tell me that he disconnect the call. I know that I was rude but all he could have told me why was at his account unable to do the upgrade and why was account have that error. Few months back I was able to a upgrade on 1 of my other numbers with NO PROBLEM AT ALL. I want Cell Cto explain to why not.