Vodacom keeps saying I owe them money and I dont

I complained last year. My complaint: Vodacom cancelled contract but I keep getting messages that my account is in arrears I had a data contract with Vodacom. I had issues with connection. Vodacom cancelled my contract due to network issues not being resolved. They arranged for collection of the router meaning my contract with Vodacom is cancelled. I keep getting emails that my account is in arrears. How when Vodacom cancelled my contract? I sent an email but they referred me to a website where the bot is so useless. Please stop sending me emails as my contract has been cancelled by Vodacom.

Vodacom rep**** to say they have sorted out the matter and I do not owe anything as they are the ones who cancelled my contract. I am stil receivng calls and emails to say my account has been handed over to debt collectors. How is this even possible when Vodacom informed me that this issue was sorted?