Do you sell unlocked phones

Yes a few different brands and networks

Yes

Yes Best Buy sells Samsung-Motorla-Sony-BlackBerry-Apple and more.. Hope this Helps You

But they don't sell replacement batteries for your cell phone when you need one.

Yes. Thry have hauwei, essential phone, samsung motorla, blu, sony, asus, lg,bzte, Blackberry and apple

Yes they do, they offer you phones with a company or without it(unlocked).