Def complain - unless its highlighted to the store that this is happening no one will know and nothing will happen. imagine if you were a mystery shopper the store would of scored so badly. Its not a lot to ask for. I love mystery shopping and will always be honest, I've been one store and the staff were amazing and this is what I reported back, on the other hand I've been places where its really bad and have reported this back as well.
On the other side - staff can't always complain about customers and yes the customer is always right - but that's the nature of the business, perhaps staff who can't cope need better training from the company on customer service. I advise staff to always be polite and calm no matter how irrate a customer becomes, often this will make the customer calmer and feel silly for being so angry. The �3 an hour is below minimum wage, and that person should check this further.
I was raised to be polite to people, hold doors open, give up my seat etc etc and I retain this values and feel its such an important thing, young people today aren't taught these values which is a real shame, equally older people don't always say thank you when you do things.
Maybe citezenship lessons in school should have a module on manners