Denny's review: Denny's has a sign posted in restrautrant that they offer Veteran's Discounts

The last three times I have visited Denny's on West Lake Mead Las Vegas, NV 89128. In those times I have ordered from the menu. I understand that ordering from the 55+ menu the restraurant offers a lower price, and that is because less food is given for that meal.
I have always asked if they give a Veteran's Discount. Always the answer is yes, until I get to the register. The young lady working the register looks me in the eye and states no Veteran Discount given, because we have already given you the lowest price.
Do your employees understand that less food is placed on plate for the 55+ menu items. In anycase if anyone can get back to me and explain the restrauants ploicy for giving discounts.
If a discount is offered then your employee's need to comply, or post any limations!