Contract cancelled 3 months later request payment

At the end of May 2015, I went to Altech Autopage offices in Rustenburg, Platinum Square Mall, to cancel my existing cellphone contract. The lady who assisted me, did not request any identification, she did not ask me to sign anything. On my enquiry if everything is in order now, would anything else be expected of me, she confirmed that everything is in order, the contract was cancelled. In the beginning of June, the debit order was reversed, by Autopage. Since then no payments was deducted from my bank account. I was very impressed with them, because everything went smooth, no hickups. Then all of a sudden, on the 28th of August 2015, I receive SMS messages to 3 of my 4 cellphones, which I have contracts with Vodacom, informing me that I am in arrears, and if I do not pay, they will place me on the Credit Bereau. My wife contacted them with the informaiton, and Marvin, who assisted her, confirmed that they made a mistake, and all charges will be written back, call reference no 681247 applies. In last week I received yet another SMS informing me that I owe them R544.59, because I did not give them 2 months notice, and threatened with the credit bereau once again. What now?????