Woo, another way to get out of your contract!
If I were Sprint, I would set it up so that the system recognized phone numbers that called in frequently. And it would put those numbers in a separate queue. This queue could either put them on hold for an hour before finally connecting them to somebody. Or it could say something like, "Quit complaining, you big complainer!" and hang up on them. Maybe it could refer them to another carrier and Sprint could get referral fees.
Calling them a complainer and hanging up on them is a perfect solution, though. The customer will either get pissed off and leave Sprint or they'll realize that they complain way too much and they'll stop. I wish Sprint would consult me about these things before making important decisions.