Markham ****!!!!

Markham have an ad online of blue MKM pale blue slim textured suit trousers. Online there is a 25% off Markam and relay items. They did not specify if it was online or not and there is a tab to check in store availability. I checked the availability and they said Centurion mall Markham had 5 stock. When I drove to the store I was told that they can’t help me because it’s not on sale. I showed them the online search and that the offer ends 20 September. So now I need to understand how sales work with such a big brand and how come the other stores did not know of the sale. There was no indication on the ad that it was online only