Thank you for giving us this platform to ask questions.
And my question – is there a measure or lasting solution that can be put in place to workers stealing customers at place of work?
This cannot be tolerated, and you must be clear about that with your staff.
It’s very difficult to track. But you can’t allow your staff to literally steal the food out of your mouth. You have won the customers by marketing, advertising, building a reputation. All of these things come at a cost.
You are not only spending the money to win the customers, you are also paying the staff to work for you. I doubt you can afford to incur both sets of costs without making a profit from transacting the business yourself, or on your own account.
I should make sure everyone knows that you are aware this has happened and that it is not acceptable. Anyone found to be doing it will be dismissed with immediate effect. Write it into their contracts, the employment manual, and put up notices in the staff rooms. Then if anyone does it and you can prove it, I would dismiss them immediately.