You might be a Bad Customer if...

if you buy 10 cent candy to break a 20
you have to separate transactions for two 2/$1.00 candy bars (but then how would I know how much they are apiece?)
you think the Pre-pay sign on the gas pump is for everyone but you.
you ask for a bag, big printed receipt, etc, when you feel you have been overcharged for something because you want to get the most out of the company.
You can't read the signs or coupons correctly, insisting you're right and all the employees are wrong.
While standing in front of the huge of TVs, you ask a salesman, "Is this all the TVs you have?"
You dare ask for a discount at a restaraunt because your kids didn't like thier food after they showed their dislike by throwing said food on the walls and the floor
you chew out the manager of the local McDonald's for not cleaning up the place, while meanwhile, your kids proceed to launch ketchup packets at each other.
you pay anything / everything in small change (especially pennies)