Done with Cell C - dozens of calls, hours wasted, no resolution to simple problem!

Wasted another 1.5 hours of my life this morning trying to get Cell C to resolve this issue. Spoke to 8 different agents in 4 different departments, transferred back and forth, given numbers to call that don't work, had the phone put down on me, absolutely digraceful service! This sim only data contract was supposed to be cancelled on 10 July, nothing happened until 11 Septemeber after numerous calls to get it cancelled. Cell C have debited R1755 from my account for something I have not used and should have been cancelled more than 2 months ago! How do I get my money back???