Hi Walkerboy11
Thanks for your post.
Any iPhones purchased from Carphone Warehouse will lock to the first network they're used with and this is an agreement Carphone Warehouse and Apple have come to.
If this wasn't advised to you when you purchased the phone, you may have reason to dispute with Carphone Warehouse.
To be clear, we don't play any part in the handset locking to one of our SIMs if used in one of these phones (technically it's actually EE that the iPhone will lock to).
If you have an active mobile account, we can look into getting this unlocked for you, but you do need to be an active customer of ours for us to be able to do this.
Many thanks