Inability to terminate my mobile contract

My contract has reached the end of its term, due to constant network problems and bad service i decided to move to another service provider. On Sunday i went into the Southgate branch to terminate my contract, i was told i could not do so as their lines were down while another person was being assisted. Today i have called their call centre multiple times trying to cancel my contract, but all of these attempts end with me being put on hold for more than 15 minutes up until i hang up. <br> <br> I would like to know when i will get assistance as my contract ends at the end of the month and i do not want it to be renewed, because of past bad service from Cell -C,i KNOW that at the end of the month,and even the following month i will be billed for a contract that i have been trying to cancel.<br> Please help,as i have exhausted all my energy with cell-c.