Bad experience with SellDirect

I was due for an upgrade on my Telkom Mobile contract. I did upgrade via telephone with SellDirect on the 15 November 2018. I received my new handset on the 19th of November. Unfortunately the screen was cracked and Sell Direct did come and collect the handset. They send me a new one, unfortunately it was the wrong color, and they collect again and send me once again a new handset, wrong color again. Eventually I received the correct color on the 14th of December. Unfortunately the phone was faulty again and did not work properly. They collected the phone again, but now they say it does not fall under the 7 day OBF (Out of Box Failure) policy and needed to go in for repairs, but their technical department is closing on 21st of December and only opening 7th of January 2019. That means it will be more than 2 months since I upgraded that I will receive a new handset, although I already start paying for something I do not have. I requested to cancel the contract with them and rather go to a Telkom Mobile store directly, but they refuse.