Dominos Trying To Take Away Delivery Driver Mileage?

Okay for context, when delivery drivers are in the store one of their main jobs is to keep up and maintain the dishes. Recently the store made a change so that if you’re not using the dishrag at that moment then it’s supposed to be soaking in sanitizer, as opposed to just laying it on the side of the sink like it has been for years. Well today someone left the dishrag laying out, and my employer is saying because they didn’t see who did it they’re taking 1 delivery worth of mileage away from all the drivers on shift tonight. The mileage rate is only $1.75/delivery, but for me it’s about the principal and the fact that they may, in the future, continue to dock pay from employees who did nothing wrong. So I guess my questions would be, is this legal? And if not who should I report it to? This is in Georgia.