Advertising blunder

I visited the Checkers Retail Park today after seeing a special offer on your website: 2 for R249 on Parmalat cheese 850g. At the store, I was informed that this offer is supposedly only valid for 60Sixty deliveries. However, I tried using both the 60Sixty app and the website, and in both instances, the special price disappears as soon as I add the product to my cart. I consider this to be a possible error or a misleading adverti*****t, and I kindly request that you investigate the matter and confirm whether the offer is indeed valid.