Charged the whole month for just 2 days activation

In January, I called DSTV to rectify my account as I was charged for the whole of December subscription, but only had it activated 2 days via the Whatsup self service. I phoned a few times since then and the "manager's "was going to phone me. Till today no one has phoned me and my account is still not rectified. I cannot be charged if DSTV's self service did not deactivate the account. I want my reimbur*****t please.