Cancelled contract...Now I have to pay months later

I am very disappointed with dealing with Vodacom. I have cancel one of my contracts with Telkom in March 2023. Saturday the 12 August 2023 I get an SMS stating that I know owe Telkom over R2000. How does this make sense when the contact was cancelled. and now get told I will be handed over if payment is not received. I will not make a payment for a contract that was cancelled in March of this year. I would like this to rectified as soon as possible. because to get through to the call centre is utterly useless and in the store they just state it cancelled.

So can anyone do their job and correct this issue!!!!!!!!!