I had the same issue when on to customer service. They added a good will code to my order which was about 20%. Also sent a screenshot to them to show I was offered the discount and they should be investigating and give me something on my account.
Hi, I had the same problem and Samsung emailed me to advise the following: Please note that this offer is “20% off New Galaxy watch, any Galaxy book and Tab S7 range when you buy the new Flip and Fold Smartphones”. luckily I had a 15% code via email that I could use instead.