[Political Junkie Too]

The employee can try to claim a hostile work

That only applies to employees and management. Customers can't be sued on hostile work environment grounds.

-PJ

[T.B. Yoits]

Employees can claim a hostile work environment and sue the company if they can show a pattern of management not dealing with abusive customers.

https://www.hourly.io/post/customer-harassesing-an-employee