Poor customer service and not honoring what they promise

on the 13th of November 2021 I went shopping at the Sherwood store, when I got there they had a promotion on the 2kg Skip washing powder, but they didnt have it in store, I was then given a raincheck with the promise that they would call me whenever stock becomes available, I kept going to the store and they didn't have stock, today when I called to follow up a lady by the name of Simphiwe said they unfortunately cannot help me with the raincheck, it is very disgusting because I went back to the store several times and they never said this they kept saying as soon as they receive stock I will be assisted, what has changed all of a sudden, why am I even the one who has to call them before I can be told such.