O2 are literally the worst! Customer service is non-existent! Avoid if you can! I upgraded my phone and paid a significant amount towards the device however when I received the phone it was faulty! I called o2 and asked for a refund, which they agreed as part of the T&Cs of my contract. I sent the phone back as instructed and since then, I have been waiting 3 months for the refund to be processed, no one takes any interest in helping me when I call their call centre, passing me from one unhelpful person to the next. I’ve tried emailing them, and even sent messages to their Twitter team with no response! They promise call backs from Managers and the Customer Service Team but these calls do not happen! They are beyond awful - I just want the refund that’s due to me!