Disgusted!! Vodacom useless

I cancelled my contract with vodacom over the phone months ago. I was on the line for ages. They kept debiting me for a contract I was not even using . I got a call this morning to say I owe R6000 plus on my account.

I told the lady it was cancelled last year aug sept and she asked for my reference number as if it's my job to remember that . It should be on their system .

So she was quiet and then hung up . Bladdy rude !!!!!! I will take this much further as I refuse to pay for something I cancelled