Bad Customer service

I bought an DSTV explorer at Game Stores in Cape Town on the 23 of June 2018. The sales gentleman said Wi-Fi holder was out of stock. He took down my contact details as well as a friend of mine. Because we both bought an explorer each. He said that we will be phoned when they become available. The friend of mine went again the following month and they were still out of stock. I moved house in October 2018, and my explorer was installed by a DSTV installer. Then I went to the store in November 2018 to ask if the holders are available. But since I moved I noticed that I had misplaced the receipt. I went to the store and explained my situation. Luckily for me I saw the sales gentleman that wrote our contact numbers. He then said to me do I know that this is not internet, what do I need this for? He ridiculed me as if I cannot claim this as I won't know what to do with it. Eventually he said that I must go to the accounts department. They told me that it will take forever to get the receipt and that they will phone me. Till to date they have not phoned. And I feel it is unfair because they advertised the explorer with the Wi-Fi holder so why should I not receive it.