Account being billed after contract expired

Hi <br> <br> My contract expired in February, but I was being billed until I called them in March to cancel the contract.<br> <br> the lady I spoke to Sharon Yon, told me I will be debited for April even though I will not be using their services. <br> <br> I haven't being using their services since June 2014 because I moved work places but I let the debit orders run until the contract expired because I didn't have time to personally come in (as per one of their consultants) to cancel the contract. I am really annoyed by the fact that I have to deal with this lady back and forth teaching her how to do her job and its not really about the R150 but more about business principals. why should I be charged for services I will not and have not been using for 6 months