Iphone and blackberry messaging problem

Okay, so i had an iphone 3gs, all was working well until i was playing football and it fell out my pocket.
The screen cracked and the touch screen underneath no longer worked.

i switched my simcard to an old blackberry i had, and it all worked fine.

However, when i try text a friend who uses imessage, his replies come through on my iphone, and ovcourse there's no way for me to reply, or to turn off imessage on my iphone because my touch screen doesn't work…

any suggestions? If i just drain the battery on my iphone will the imessage automatically go off?

If you turn the iPhone off then no iMessages can be sent through to it. It will continue to receive iMessages even without a SIM if it is still picking up a Wi-Fi signal, so if you can't use the touch screen to turn off Wi-Fi on iMessage on the iPhone - just turn the phone off.

Then if you have your SIM in a Blackberry your messages should then just come through as normal text messages. If you are going to continue to use a BB you might want to let your network know so you can switch onto a Blackberry plan and get inclusive use of BBM, emails, internet etc. For £5 per month.