How to go about unblocking an iPhone on orange?

I recently had my iPhone stolen on holiday so have brought a new one of gumtree. It is a brand new iPhone and not stolen (the man i brought it off renewed his contract and they send him a new one but he already had one so sold it) The iPhone is locked to orange and I have a t-mobile sim. I haven't set up the phone yet as i don't know if it will work with this sim in (will it?!) And i was also wondering how long would it take shops to unblock it. Obviously i would turn it on for them to do this! Seriously any help it appreciated on this x

If the phone you bought on Orange and you want to use it on T-Mobile then you need to get it unlock either going into some local shops or using online services from www.thephonebox.net if you e-mail these people they will be able to unlock your phone on cheap and good price. But make sure it works on Orange network first by putting any Orange Pay as you go sim card in it to make sure the guy you bought it off is not scam or sold you the phone and then reported lost or stolen to get a new phone for himself. If it works on Orange then all you need to do is get it Unlock which is cost you roughly about £30-£55 and takes upto 1-14 days.

Best option is after checking it works on Orange contact The Phone Box.