Make sure you state what the Company requirements are and why. Tell the associate that there are 20 other people on the roster begging for hours and will bounce off the walls in to be here. Politely warn the associate if there performance doesn't improve then you will call another associate in and send them home for the day. Then let upper management know the reasoning behind the change.
We had a customer who had a mental disorder as well as some problems with the law. She had definite mood swings and abused the refill policy. After a number of little interactions when she was asking other customers for money and we had to ask her to stop, as well as after having to explain that the first drink had to be purchased, not just fibbed about and "called a refill" we eventually had to be in pretty regular contact with police who offered to usher her out any time she was causing commotions. We were always courteous with her and gave her what we could and were supposed to, such as a refill if she stayed on the premises, but we had to draw a line between making the customer happy and helping a customer steal from the company.
1. Listen. 2. Ask sympathetic questions. 3. Listen 4. Try to come up with a viable offer/alternative which either removes any concern or at-least show that we care. 5. Listen 6. Discuss options 7. Listen, assertively. 8. Regardless of the outcome thank customer for being our customer in a way that it distances him/her from the current situation and bring the fundamental relationship in the picture. 9. Listen. 10. Recap the action items/next steps.