Welcome to Vodafone Community
There are plenty of previous threads about unlocking an iphone. You should have had some search results come up when you started your thread which would have given you the answer.
As the phone was on a contract, only the original owner can complete the form and get the unlock.
As far as I am aware, if it is a VF supplied handset, then Apple will only accept unlock requests from VF
If your friend gave/sold you the phone, then it shouldn't be too hard for them to fill in the online form to request the unlock for you?
(removed link as per T's&C's)
I called these guys and had a chat. They said it can be done...
Unfortunately that is not an official Apple unlocking. As Jeffkinn said, you can only get an official unlock done by going through the network provider who in turn contacts Apple. I would be very cautious about parting with my money to some random website (all of whom will tell you that they can unlock your handset).
I would advise you do a quick search of the Apple forums and you will find that everyone gets referred back to the network provide to whom the handset is locked.