Default [Q] Sim unlock site recommendations?

Folks

I have an S4 on EE (UK). Completely stock - not rooted either. Latest ORA updates. I got it in Feb 2014 I need to use it for a couple of months with a Vodafone SIM.

Are any of the SIM unlock web sites reliable and do they work? Can anyone recommend one for me please

Many thanks
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iPhone 5s (ok, don't give me hassle )
Jailbroken
Samsung S4 (factory)
Asus TF201 32GB (UK)
Rooted and Unlocked!!!!
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