Cancellation of Contract

I cancelled contract in June, I was given the cancellation amount by the retentions department. I paid the amount and it turns out the consultant gave me a higher amount which I paid and I am now due for a refund when I look at the bill. I have been calling but no feedback, queries have been logged with the retentions department and ignition company that works with MTN but I get no response. I want my money MTN has bad service and the call centre just keeps on cutting my calls. I am not happy with their service at all! I regret taking contract from MTN!!