Horrible service from Cell C

Hi never wanted this situation to go this far, but it seems i have no other choice. I have had my mobile number since 2011 with nashua mobile them migrated to Autopage, glocell and then eventually Cell C. So as you can see i had this number for quite some. Over the years i had few to no issues with Cell C. Apparently last year i could not do an upgrade on my number because my number is linked with someone else's ID number. Ive called the call centre multiple times with no avail. i was told to go instore with my ID document which i did. I was told to go to home affairs because someone is linked to my ID which isn't the case. So now in the whole of the cell c organization there is no one that can assist me. Ive been a loyal customer for many years with multiple contracts. I therefore stopped paying account. I must express that i am bitterly disappointed with Cell C. The only reason i have been paying out of contract fees was for the fact that i do not want to lose my number. I have been basically paying for the device after the contract has ended because i can't make changes due to the fact that its not on my ID. Why must i pay and struggle for a mistake on Cell C's side.