Ignoring request to make use of cooling off period and not completing bank verification at all

Sell Direct Marketing contacted me with regards to an upgrade that was due with Telkom. In spite of the fact that the debi-check never came through to my bank account and therefore not approved, that phone was sent, which is against the terms and conditions. My main recourse was the 5 day cooling off period which I am entitled to as per the Consumer Protection Act and I advised them of my intention to make use of this. I have had no response and still have the phone with me. If they were going to deduct a subscription, I do not even know how they will gain the necessary approval from my bank. Setting this all aside my right with regards to the cooling off period is just completed ignored and is a right that we have an Act to protect us. Someone from Sell Direct, please make a plan, contact me and get this phone sent back, as is my right. Thank you