They could never get my bill correct and if you looked at it, it'd be weird things like double-charged, adjusted, extra charges added and then removed randomly - all on the same bill. I thought it was just me until I saw an article in 2600 where someone else posted his bill and it was messed up like mine.
And then, every couple months, my service would be shut off for non-payment (even though I mailed my payment weeks prior). I'd check my bank and the check went through and so I would call Sprint and get the runaround. Finally started paying over the phone so I'd get the confirmation number. Which would lead to the following telephone calls:
Sprint CSR: "Yes, we're showing that your service was suspended due to non-payment, but if you pay..."
Me (interupting): "Confirmation #638749979" (rattling off whatever the confirmation number was that month.)
Sprint CSR: "Yes, I see that you have paid. Let me apply this to your account. Your balance will be zero and you'll be re-activated."
This happened about 7 times over 1.5 year period (Around about the time of the Nextel merger). The last time it happened, I told the CSR I just wanted to cancel my account; I gladly paid the ETF on two accounts.
I suspect it had to do with using a work discount, since everything seemed to be billing issues. I'd never go back to them, though.