Why are the coupons a lie?

Two for 12.99 coupon only lists cheesy garlic bread as exception.

Go into subway and there's an exception list that says basically any sandwich other than the most basic can't be applied to coupon.

Thing is, the coupon doesn't list exceptions and I don't believe it's a legitimate practice to lie to people to get them in the door.

I went in wanting a sub club, ended up with a basic turkey sub that I only saved about 50 cents on.

Who is lying the workers or the coupons?

Isn't standard practice to accept the coupons and the coupons listed exceptions?