Incorrectly billed ONCE AGAIN

Vodacom called me to sell me a WIFI device. THEY CALLED ME. I took up the deal and contract and the device in June sometime. I had to call the after sales department every other day to have this WIFI device connected. I called about 6 times, everytime I was told, it will be connected within 48 hours, once the 48 hours lapsed, I called again only to be told the same story. After many attempt to have the WIFI connected, I was told Vodacom is experiencing technical issues with their devices. I then asked for the to collect the device and cancel the contract. The lady I spoke to ENSURED me that the new contract has not been activated because the device was not activated, therefore I will not be billed for it. Guess what? That was not the fact, I have been billed for a device which I do not have and am not using. I called the helpdesk last week to find out what was happening on my account, and was told the device was not received, after holding on for 15 minutes the agent then told me no sorry it has been received. Assured me my account will be sorted and I will not be billed for the device in future. I am getting automated calls from Vodacom every day reminding me to settle the outstanding amount, otherwise my phone number will be blocked. Can some competent person please sort out this mess created by VODACOM???