Worst experience ever!!

A sale item was out of stock and I requested a rain cheque. A rain cheque was provided but upon my return to the store to claim the items, I was told that they could not help. Apparently the item package were limited and they do not have the free basket. Apparently the supplier misinformed them. I then responded that I would accept the loose products instead. I was then told I must take it up with customer care and the supplier as it is not their problem. I have spoken to Mariska and her assistant at the branch. They were very unprofessional, spoke over me as I was talking and made me felt like I as a consumer do not have any say. Your rain cheque clearly states that I may have the items for the advertised price. Nowhere does it say that I need to call the supplier nor does it say that I can be refused these items. Is a rain cheque not your promise to your customers? I am disgusted in the manner this matter was handled and want you to keep up your end of this promise made in a rain cheque.