The Brick review: ADW78TVS

I would like to file a complaint for The Brick - Heartland Mississauga location. I went in the store to purchase the product with the number ADW78TVS in white which was marketed for $399.99 with a sign directly above it that said Take 15% off this price. When I asked the customer service to help me with the product they informed me that the product is already on a reduced price and cannot be discounted. I would like to remind you there were no signs mentioning the original price or that stated its 15% off the original price. I was denied the offer and embarrassed for even asking for what was promoted. Someone who has worked in retail for years I have never heard that we will not abide by our mistake and honor the price we advertised. I also have a couch order (0504353OKAO) pending with The Brick and had plans of buying other pieces of furniture from The Brick but to think a big corporation would deny a minor discount which was basically honoring their mistake and losing a customer over it is beside my understanding. My hope is that you simply just honor the discount otherwise that's fine I would just politely take my business elsewhere. I am attaching the pictures of what was advertised.