Cancellation of contract

I completed the forms for cancellation in 24 December 2015. <br> <br> The cancellation forms was not received by the processing office. The branch was at fault. I sent the cancellation to the person assisting me. I was migrated to prepaid. I still have the matter of the airtime that was transferred and was nit supposed to be.<br> I was promised that the billing department would contact me arrange for the airtime that they loaded to be reversed.<br> This was in January. To this day nothing. I have been following up via email though I have not received a response. <br> <br> I need this resolved like two months ago.