Im on pay as you go and i find it really hard to understand how contract phone work so i was wondering if someone could please help me out with this question...

Is there anywhere i can get a HTC touch diamond phone for free and only pay a total of £20 or less each month (with the deal having at least 200 texts as i text quite a lot)?

Thanks for your help. I would really appreciate it if you could send me some links to websites or website names etc.