First there are NO unsuspecting CM's at WDW
Second- you can use your old mugs in various ways
1. Pen & Pencil holder on your desk
2. Makes a great toothpaste and tootbrush holder in the bathroom
3. You have 8?? great !! set up mugs, grab a small ball and let the kids play Bowling with mugs
4. They are great to keep in the car to sneak into 7-11's and get cheap refills Just cover your mug with Mickey stickers... no one will notice
5. keeps the sun tan lotion and other liquid filled containers from rolling all around the trunk of your car and leaking all over
6. They make cute flower pots..
7. Take them to the beach to make sandcastles with..
8. re -gift- fill them with Mickey confetti and give to friends and family who haven't been to Disney.
9. Use them at Christmas- put small presents inside and no wrapping involved!!
I'm sorry -I am being bad....please don't get upset..
in all seriousness I have no idea on policy about trying to pay for already bought mugs. Someone around here should know- I just know that they use wire clippers to clip off the tabs on them after they are bought so I wouldn't think you can repay for them but who knows..