Not honoring the special discount advertised!

Sneaker was on sale during the day. Saw the advert on social media! (And all of last week!) Purchased in the evening thought the discount would happen at check out. I Purchased it anyway as I was worried that my size would be sold out. The next day the advert was on my social media stream again! When queried I was told the special was only activated at MIDNIGHT?? A few hours after I purchased my sneakers! But the discount was visible during the same day of purchase. So what happened in the few hours I made payment? R 180 difference is not really the issue, it’s the PRINCIPLE. The fact that the 10% wasn’t working when I checked out is the problem! I know that 10% was advertised during the day! All of last week too! It’s a pity this happened as the delivery and everything else was good. On time, professional and so easy! I’m angry as you should have honored the 10% discount! I paid R 1799.00 R 1619.00 was what I should have paid! First and last time I use Superbalist!