You know what you do? You go right back up to the counter and tell them "I WANT MY MONEY BACK!" and if they give it back fine, but if they start telling you that you have to contact corporate just stand there and keep saying over and over again "I WANT MY MONEY BACK!
THE SANDWICH WAS OVER 50 PERCENT! GIVE ME BACK MY MONEY!" until finally they are either going to give you your money back so that you don't scare away other suckers, I mean customer, or they will tell you that you are going to have to leave or they are going to call the police. If you then keep saying "GIVE ME MY MONEY BACK! THE SANDWICH WAS OVER 5o PERCENT FAT!" they will either realize that you have called their bluff and refund your money, or they will pick up the phone and call up somebody that WILL remove you from the store and probably take you to jail.
If you don't wanna risk calling their bluff, leave and go get yourself a real big rectangualr square of cardboard and a marks-a-lot and make a sign saying how you got gyped at Arby's and how your sandwich was over 50 percent fat and that they wouldn't give you your money back. Go hold it up near the street in front of the restaurant homeless panhandler style so that everybody driving by will see it. Somebody may even take pity on you and over to "Refund" you the money out of their own pocket just to make you go away.
Or maybe the store manager will go outside and give you the money. Or, you could just save yourself alot of hassle and decide that you are no longer going to go back to their store again, and chalk up the money wasted on your meal as tuition in the school of hard knocks.
Arbys Pros: I love arbys roast beef sandwiches.
Arbys Cons: When my local store went out of business.