Telkom and Sell Direct ignore cooling-off cancellation

My 24-month Telkom data contract was due to end. I was approached telephonically a few days prior by somebody claiming to represent Telkom and in possession of my ID number and account details, offering me an upgrade to a deal that I knew Telkom was offering. Believing the person to be a Telkom employee, I agreed to a contract upgrade. Three days later, a data modem device and SIM card were delivered to me by courier. In the box was a pamphlet with Sell Direct branding, a contact number ( ********** ) and details regarding my right to cancel within a 5-day 'cooling off' period. I was completely taken aback that the device was not from Telkom, that there was no written contract either in hard copy or via email, and that the other party in the agreement appeared to be Sell Direct rather than, as I had thought, Telkom. I did not open the device, instead contacting Sell Direct by phone the following day and instructing them that I had no knowledge of having entered into a contract with them and that the device could be collected and the 'contract' cancelled. At this stage, my existing Telkom SIM card ceased to work and the accumulated data appears to have disappeared, although I did not sign a new contract and I did not open or activate a new SIM card. I was invoiced for the full month . After I followed up with an email to Sell Direct indicating that I wished to exercise my right to cancel within the 5-day period and again telephonically, the device was collected by the same courier from the address to which it was delivered. I have a copy of the waybill on file. To the best of my knowledge based on interaction with Sell Direct's call centre, and based on the fact that my Telkom My Account online portal still indicated that I was eligible for an upgrade, I have not entered into any new contract with Telkom. I am not in possession of a new device, and have not received data or any other benefits. I have furthermore not been provided with a copy of any contract, as would be required in terms of relevant legislation. I have no knowledge of who Sell Direct is or what their relationship is with Telkom, other than that based on my experience so far and on various online reviews it is an extremely problematic company with non-existent customer service and ********** marketing techniques. Despite the follow-up requests copied below, I received no written confirmation from Sell Direct that a cancellation had been effected. Instead, my Telkom My Account now indicates that a new contract is active. I therefore on initiated a cancellation process via Telkom's website. Not having heard anything, I followed up with a call today and spent about half an hour on hold for a supervisor (Noluthando Sishi), after which I was advised she would call me back urgently. Needless to say, I'm still waiting.