I will never get the people who complain about customers when they work retail. The answer is simple: Stop working in retail.
normally yes, but the way things are these days a lot of people don't have much choice
definitely try to get out as soon as possible though, I've worked in something pretty close to a sweatshop and it was preferable to any of the jobs I've had where you have to deal with customers. honestly the whole experience left me feeling like humans are probably a lower form of life than chimps, the average american wishes they were sophisticated enough that throwing their feces at each other was normal behavior.