Contract expired but still being billed

At the end of April 2015 I phoned Autopage Thabazimbi, informing them that my 2 years of bad service from Autopage had come to an end, and that I was not interested in renewing the contract.<br> the lady informed me that I should give a months notice, and that it should be the 1st of May 2015.<br> on the 1st of May 2015 I went back to the store and told the lady that I wanted to give my notice, she slapped some keys on the computer and told me all is done, she explained to me that because it is the 1st of the month I will still receive my airtime on the 1st of June and will still be liable to pay the account on the 1st of June 2015, I asked the young lady if I pay the account if all will be done, and if I will still owe Autopage any money? the Lady assured me after the 1st of June I would owe them nothing! on the 1st of July the Autopage debit order still went off, I phoned Autopage head office to ask as to why this happened, the service desk agent who took the call listened to my complaint and then transferred me to another agent, she listened to my complaint and the transferred me again, and as for some one helping me I am still on hold and still don't know why they took my money