If you are polite I don't think customer service in the UK is that bad in fact I think it's pretty good.
M&S spent 30 minutes trying to find me a waistcoat for a suit I had selected.
The biggest issue with customer service is being accosted as soon as you walk through the door.
My most amusing bad customer service was in a restaurant where the food was barely edible. When the waitress asked "Is everything okay with the food?" I began a 10 minute diatribe pointing out all the problems we had to which she replied "Oh, okay". We never saw here again.
Most annoying customer service. Having to go into a HSBC bank so I could have my HSBC online only credit card activated.