Again-make your reservation on line and print out a copy.
Take your printout down and present it to the lying chimp behind the desk-ask to speak to a MOD-and hopefully the chimp will be present when you address your concerns to the MOD.
Or let them know that you do not appriciate being lied to,cancel your ressie(possible if if it a 6 pm cancel by)and head off to another chain that might show some respect for one of their best customers.