Ringtones for Phones

I currently have cingular/at&t and I’ve had it for 8 years. I am not happy with that company anymore and I want to change plans w/ a new provider. I have my own business and I use my cell phone for when clients call. My cingular phone now wont take calls from anyone. It always says “no network coverage” and I took it in and they said its the phone, not the sim card. They will only give me a new one if I sign another 2 year contract and I don’t want at&t anymore. I qualify for a new phone at the end of this month. I need a service that you get a lot of bang for the buck, lots of minutes and a good deal with texting.. I keep hearing, “use sprint” or use “tmobile”— I get a lot of different answers. I dont need a fancy cell phone, I just want one that WORKS. One with at least a camera and text messaging. I have been without a phone for almost a month and finally found out what the problem is. I’m just sick of cingular. What do you suggest? Thanks!