I had purchased an iPhone 4s from ebay that was locked to Vodafone UK. I was told that the phone had a clean IMEI and only need to be unlocked, which is perfectly legal.
After doing a search online for companies that unlock iPhones, I found www.cubeture.net and I sent them several emails to be sure they could unlock my iPhone and repeatedly they told me that they would be able.
Cubeture asked me to pay the $10 fee and that I would receive my unlock code in an email.
They did send me a sequence of numbers but nothing that would unlock my phone. I tried to ask Cubeture for a refund but they refuse.
I recommend that no one else try using this company either.