Bate Advertising

Firstly Dischem does not honor the rain check slip, i had a rain check for an advertised product (Pronutro chocolate 500g) on the 21/11/2020. I was told that they will give me a call once they receive the stock. to date i have not received any feedback. On the raincheck slip i see an 30day from issue of slip. This is what is known as bate advertising. Please could someone assist me with this