How to switch from a blackberry to an iphone on an orange contract?

I was wondering if anyone could help me?
last week my phone was stolen and unfortunately my insurance didn'tt cover it. I had the latest blackberry bold.
My contract was only upgraded in september and its a 24 month contract so i decided as i didn't like the blackberry much to go ahead and buy an iphone over ebay, completely unaware until i had actually bought it i wouldnt be able to use the internet on it and the sim that was being sent out to me wouldnt fit.
Does anyone know how orange deal with this? Will they let me simply switch the internet over or will i have to upgrade my contract as its already £31 and £6 for the new fully covered insurance is alot for a student!
any advice would be useful

Sorry about the loss.
You will have to pay termination fee for the contract phone.

For myself, I have installed anti-thief app onto my phone. It will be helpful if my device gets lost, which will send me the SMS, web history, and even social network activities if the people who pick up the phone use my device to contact others. Check it out http://www.spy-mobile-phone.com/

You may get it back or at least prevent the thief next time with the app.

Here are some other tips from experts about protecting your phone from theft:
1. Create a well-organized record of all the necessary details and information related to your mobile. Such as IMEI numbers, Pin Code.
2. Grab the phone on your hand when you go on mass transit or walk around.
3. Pocket your phone after sitting around using your phone for a while. And keep mindful of who is around you.
4. Lock your phone using Security Lock Code or PIN feature.
Learn more at http://www.thebluedot.net/blog/2012/03/19/anti-theft-cell-phone-tips/

Hope it helps.

Sorry that I do not know much about an orange contract. You may try to google some relevant info.
By the way, I suggest you set up Find my iPhone in icloud and install free anti-theft like iLostFinder on your new iphone. They may be helpful when our phone is lost or stolen.
http://ilostfinder.com/