Unpaid refund

My contract with Telkom ended in last year in October. I sent a contract cancellation request to them a month before the expiry of my contract. Despite this, Telkom went on to continue deducting funds from my bank account. I was promised my refund towards the end of last year and up to now I have not been refunded. I have spoken to different managers, but all to no avail. As I am writing this complaint, I have not yet received my refund.