Hi there, I have a question. About a month ago, I purchased an iPhone 6 on ebay classifieds with an UK O2 sim lock. The seller also gave me a sheet of paper from a lost & found office that the periode of 6 months was over and he could keep the phone. Anyway, I tried to get the simlock removed but o2 sent me following explanations: I'm sorry, we have not been able to unlatch your device at this time. The reason given is: The mobile number provided has not been used with the handset IMEI provided. The two will need to be associated before we can unlatch. and I'm sorry, we have not been able to unlatch your device at this time. The reason given is: You have not passed our security checks with the information that you have provided. Kindly check that you have provided the correct information. Therefore, I sold the phone further on eBay as a defect, saying "I am selling an iPhone 64GB in space gray with o2 uk simlock. I bought this device myself recently on eBay classifieds and the seller has unfortunately concealed that it has an o2 UK simlock, and therefore I cannot use this device. Therefore, it is expressly sold as a defect. Since private sale, no return or warranty!" Now the buyer requested reverse transaction, as the IMEI of the phone is apparently blacklisted and therefore, he is also unable to unlock the device. Do I have to take it back? I didnt know the IMEI was blacklisted but I expressly sold it as a defect. Any Ideas?