Sorry, not really an AIBU but I am fuming and don't want anyone else to get caught out like I was.
Long story short, I was called by someone claiming to be from Orange offering me an upgrade on my phone, which has just come out of contract. They had all my customer information and asked for letters from my password etc., very professional. They offered me a new phone and talked through the various plans available. They then said they were actually the Carphone Warehouse but were authorised dealers for Orange.
I was online at the time and checked out the deal, it was the one that the the Carphone Warehouse were offering and as it was impossible to a) get through to Orange on the phone about an upgrade b) use their site to do it online as it kept crashing, I thought 'well, at least I've heard of the Carphone Warehouse' and agreed to the deal.
I was told that my phone would be with me in 2-3 working days and if there were any problems to call 0844 89393 for their customer services. Well, 3 days came and went, I called the number and was on hold for nearly an hour being told I was 'number 2 in the queue'. Gave up. Tried again the next day (I know, I know) and ended up on hold for half an hour again at 'no 2 in the queue' before I gave up.
I then googled and found this: www.whophonedme.co.uk/08448933933 and it turns out it's a massive scam and I'm going to get a huge phone bill (£1 a minute - aaargh!).
I'm so furious with myself for being taken in and I'm going to report them to the police, the Carphone Warehouse and anyone else I can think of, but just wanted to warn others - I thought I was fairly savvy about stuff like this but these people are extremely professional, highly plausible and worse, know ALL your personal information.
Don't be taken in like I was!