I'm wondering if they made changes to your plan that have renewed your 2yr contract. If you were on an old plan and got switched to Fair & Flexible, the Nights & Weekends starting at 7pm are just part of that plan, no extra charges. Sprint doesn't have "first free incoming minute" but they do have free incoming plans, if you receive a whole lot more calls than you make that might be worth looking into.
If I'm not mistaken, unlimited text messaging is $15/month. They might give it to you free the first month as they tried to offer me, but if you forget to cancel it after that free month you start paying for it. If you renewed your contract by changing to F&F, the "Cingular offered me..." ploy won't work because that usually only works when you are out of contract or nearing the end of your 2yr agreement.
If you call them back and find that you have unknowingly renewed your contract, you can get them to reverse the changes, but only if you call right away! Otherwise, you have 90 days from the beginning of a new agreement to make changes to your plan without renewing your contract, after that 90 day period, most plan changes will renew the 2yr term.
Wow

you had a lot of questions, did I miss anything?
EDIT: Oh yeah about the SERO, I'm afraid I know nothing about that!

Are you talking about a Treo? I tried to google some info about it but it was all scattered around and I'll have to read up on it now so I know next time, maybe I can get back to you later.
