First of all, I think ANY company "
locking-in" a customer to stay with them is a chicken-dung way of keeping customers no matter how poor their customer service might be...
With that said we all have the option of signing such contract, most people are "lured" into the contract because they get to buy a cheaper or a subsidize phone. If you don't want to sign into a contract, buy the phone straight out so you won't have to stay with a company for the time that they require...
Now that I have said all of that and really do feel better
What is your reason you have when you say you NEED TO LEAVE SPRINT?
Did you move and there is poor or no coverage there?