Cell c poor service

Cell c upgraded my contract twice without my concern. At first I tried to pay it, now I want it canceled.i made million calls and they told me to send copy of my ID, Affidavit and debit order ( bank statement) of which I did but the email keeps on saying quied ..I tried to go to the nearest cell c store, they didn't help me...now am blacklisted just like that...once u take cell c contract its like u r signing for life, I wish I can get solution for this because I don't understand what am paying for...cell C is a scheme.