T-Mobile at 5232 Dempster Street, Skokie, Illinois.

Be careful and keep a close eye on what these guys do. Bought a Samsung and added it to my family plan. I told him I wanted the cheapest data option. I asked to see what the salesguy was doing with the bill but he refused and said I will show you all the details after you swipe your credit card. That should have set off more alarm bells.

Only after going home and checking my account on the T-Mobile website did I find he had upsold me to the highest speed more expensive data plan without my permission.