I opened this thread, because I got scammed yesterday, and I also can't believe that it happened to me. I'm very, very careful with stuff, but I got conned into paying for software to unlock my new phone and after paying £4.95 I discovered that I only got the software, which is free to get anywhere, and that the "credits" weren't included. Needless to say, I didn't rush to buy their "credits".
I've put it down to experience and written off the fiver. Not that I'm saying it's ok to scam people for a fiver, but it's just as well it wasn't a huge sum of money as I can ill-afford to be getting ripped off.
However, I'm now five quid poorer and feel like a bit of a tosser.