Is it possible to go to a normal phone/ bill after buying an iPhone?

I have an iPhone 3G on a Rogers Wireless 3 year contract, and I am wondering if I can go from the AMAZINGLY expensive and overpriced $80 a month plan (which sucks to say the least...I pay near to 100 friggin bucks, and I don't even get unlimited texting) to like...$30-40 for Unlimited Texting. I don't want any of the fancy iphone crap, no internet, no email, none of that crap, I just want to text all my friends. Hell..i'm even willing to get rid of the iPhone if I have to, I just REALLY want a normal phone that can text everyone. Any info would be much appreciated.