trying to cancel my contract

i when into the bayside vodacom shop in December to cancel my contract. the girl gave me the forms i filled it in. i asked her is it done now. i will not be debited again? to witch she rep**** yes all is done. i was debited for December. after i got a sms from vodcom to say it was canceled. i called the call center to find out what is going on. i was on hold for 10min then cut my line. this is so frustrating i just want to know what is going on how many more months are you going to take my money before it is canceled?