Vodacom debiting cancelled contract.

Not happy with Vodacom at all. I got a call from Vodacom sales department around 3rd of May and was told l am due for an upgrade. I upgraded to a data line with a router. I however cancelled the contract because I was unable to change the password of the router. They collected the router on the 14th of May and the warehouse confirmed having received the collected router. l am still being billed even now for the upgrade and the router. Tomorrow is the last day of the month and l will be billed too. pathetic serve from Vodacom. I will no longer upgrade with them.