Telkom over-billing

I opened a mobile contract with Telkom in July 2017. First debit order went off on August 31st 2017. The contract expired July 2019. I’ve been billed for a device I’m done paying for, not once but twice. On top of that, Telkom wants to charge me R800 for an “early cancellation fee”. They keep saying the contract was opened in October, I’m losing my marbles here and they’re sending me from pillar to post.

I’ve been trying to explain this to Telkom for nearly a month now.