Sorry this is another rant.
Retail stores should have the right to tell their employees to turn off their non-work phones. If your job requires customer service of the direct face to face kind, you should not be able to use your cell phone. At the least, it should be off when a customer is in the store. This should be an offense that merits firing. I am tired of hearing the cackling of women, the mumbling of men setting up a drinking session or skeezing on ladies, and the chitter chatter of teens who are suppose to answer my questions and provide friendly service. What exactly do you think you are being paid for?
From friends who have worked retail, it sounds like bad retail can be soul sucking work. It's still work. It's still time you are paid for, and yes it might be boring, but it is a job. If you despise it, find something else. If it's boring, find something exciting like fire jumper. People might ask you questions, and might consider you, the employee, as an expert on the very products for sale. Keep talking on the phone and adding nothing to the shopping experience, and you will be replaced by a robot. I love to go to a GNC 7 miles out of my way because of the staff. The GNCs closer are staffed by asshats that cannot stop talking on their cell phones. Good customer service gets my money.
This does not just apply to the teens and early 20-somethings working retail, as even older adults have this problem. You are at work. You are paid. Your employer and customers rely on you. Show some effort. Put the GD phone down.