[user104658]

As Kirk said, talk to your boss in writing. You have rights as an employee and your boss literally HAS to care, by legal obligation... You have the right not to be harassed or threatened (by other staff or anyone else) in the workplace and there will be someone whose job includes specifically ensuring that it doesn't happen. Any verbally aggressive behaviour could be considered threatening.

I dunno. Maybe it's because of coming from a specific customer service background that is in many ways very different to most retail - in that telling a customer "no", or that things aren't going to go as they'd like, or that they have misunderstood a product or the rules, is a very common occurrence... But yeah, working where I do, if you don't immediately take a firm stance with certain customers they will trample all over you...