Incorrect Debits

I phoned into Vodacom a month in advance to my contract end date to cancel my contract . The guy that answered assisted me well in cancelling my contract . On the last day of my contract my sim card was cancelled because i could not do jack with he sim card after that day .Its a month later and i still see Vodacom billing me for my contract that has been cancelled and the f****king sim card that is not working .I then made use of there email system on the Vodacom website to logde a complaint and it is now already 2 days later and i did not hear anything from them . Just to mention that not once did i skip a payment in my two years contract with them .This is nonsense and i want my money back asap.