Overcharged

I cancelled my contract before it ended and then I was billed all these extra charges that I don't know where they from. I called on the 6th March to query these changes. The consultant said she will log a case to fix the invoice and they will call me in 7 days. No one called. I called 3 more times to get answers and I was told the same thing that the case has been logged and I Will be called. I asked Lungile to escalate this to management and I'm still waiting. Over R900 has been debited from my account and I'm still waiting for that call. When I try to call I stay on the line for almost 20 minutes with no answer. Repay my money now before I take the legal route.