Just because you took over your own bills doesnt mean you had to leave sprint.
Thats like saying your mom let you drive the mini van but now that you moved out you can never drive a mini van and must get a truck. If your paying your own bills you can go with what ever carrier you want. It also helps us to provide us with more info so we can put that into the correct context. By simply telling us you were happy with ATT and left them we dont know you left because you were taken off your parents bill and started to pay your own stuff. Thats a valid reason to leave but with out knowing that its easy for me to guess that you left for any number of reasons. Or in my case wonder why you left at all.
I also stand by my comment about you having no service at your apartment and always roaming. I am thinking, hoping, you have learned a valuable lesson in life. When it comes to sales people they can and sometimes do have a tendency to stretch the truth. Was this a Sprint Corporate store, 3rd party, online, telesales, some guy on craigslist selling sprint service, radio shack, best buy?
The level of info people tell you is often reflected in the organization they work for and are directly trained with. I used to manage a 3rd party Nextel Service Center and i was on top of our training. But i heard so many stories from my customers about how other places similar to ours were clue less. I find that corporate stores tend to have the best trained people but they also cant bend any rules what so ever. So its a give and take. I know if i was testing a device for a new carrier and if one of the 2 places i spend most of my time, work or home, had bad, poor or no signal i wouldnt stick with that carrier.