I purchased an Apple iPhone 4 16GB Sim Free Unlocked Mobile Phone The phone arrived fine and i have no complaints but unfortunately it did not work with my O2 sim card. I was a bit confused as it had clearly been advertised as unlocked which should mean that it would work with any sim card. To be fair to the seller the description did mention that it would only work with ''ORANGE, T-MOBILE, VIRGIN, EE NETWORK UK''. So the phone wasn't really unlocked at all but in fact locked to the EE network.
I contacted the seller and returned the phone, he issued a full refund.
I would recommend this seller and use them again as he accepted my return and refunded the money promptly.
i would encourage them to clarify the wording in the advertisement about the phone being unlocked to avoid any further disappointed customers.