Poor service

I bought a muscle builder powder that was on special (buy 1 get 1 free) at Alex Mall and there was only 1 packet left. The shop assistant/teller by the name of Thato took my contact details so that he can notify me when there is stock. He called me and I was unfortunately not around the Alexandra area. I went to Click after a week or so to collect the item however I was told that the item is not available, that did not and still doesn't make any sense because I was told that I must come and collect the item. It is now almost a month and I am still waiting for the call from Clicks. My biggest issue is that I bought another packet of the powder from another service provider and therefore would like Clicks to refund me the money I have paid as they have failed to provide me with the powder, I have paid for the item but I don't have it. I need Clicks to call me at the earliest of your convenience regarding this problem. My contact number is ********** .