Debiting my account for something i dont have

I app**** for a data contract online in November 2017 but because it took so long for them to deliver, i called telkom to cancel it i even told the delivery guy who came a week later that i have cancelled it but then at the end of November i get a invoice of what i have to pay. i called the contact center again and they said that they wil escalate it. i have not received any feedback but yet i see a attempted debit order on my account for something i didn't even use or activate. so why are they even trying to debit my account after it was cancelled before i even get the package. i need this to be sorted out asap.