I Am The LAAAAAW!

"If I put something on layaway, can I make payments at any Derp-Mart?" A male Latino asked me (I'm trying to diversify my complaining from generic banshee woman.).
"No, it has to be done at this Derp-Mart but it can be paid at any register."
"Why not?"
"Because you're buying our inventory, not another store's. So the money needs to be paid here."
"That's stupid. I should be able to pay for it at any Derp-Mart store."
And I should be able to shoot you, but "The Law" won't let me.