Taking phone scammers through a reverse security check! Has to be done, and great fun!

It can't only be me who has scam phone calls come in. The most recent (and most common) is an Indian call centre voice saying that they're from my mobile phone operator, quoting (or guessing correctly) Three, in this case. They open up with 'We can offer you a 45% discount on your current mobile monthly bill'. Which, in itself, should raise alarm bells - what company ever contacts you to get you to pay them less money?? The scam itself is intended to get you to hand over all your details, of course, including payment, for the 'new contract' - and presumably your account then gets debited for a whole lot. But the point of this blog post is to point out that you should always interrupt their spiel and ask them to prove their identity. After all, it was them that called you, so the onus is on them - just as it would be if you called a company and wanted to change something in your own contract with them - they'd run you through security questions before doing ...