Tired of vodacom kuk

I've cancelled my contract last year which customer services has confirm with me. I called 2 months prior to cancellation and was advised by a agent to contact 1 month prior which I have then done and was advised that my contract was cancelled. Now I'm receiving letter saying that I will be handed over to collections if I don't pay R446.86. This is rediculas. When I called customer services they are saying that my contract was never cancelled and keeps hanging up on me. Vodacom fix this now!