If I'm on Vodafone and iv have got a blackberry can I get an iphone?

Last year I got a Vodafone contract for 2 years and it is £13 a month with a free blackberry, so I can't upgrade for another year but I really would like an iPhone so if I got one from apple or amazon, sim free, could I phone up Vodafone and ask to swap my sim I have at the moment for the micro-sim/the one I need for an iPhone? Please answer soon as I'm trying to convince my mum! Xx

You could try - i'd phone Vodafone first before you bought an iphone. Usually they will only supply you with the sim that fits the phone they gave you as part of their contract, but not sure what their stance would be as you aren't cancelling your contract you just want to use another phone. Just give em a call or pop into a shop.