I've been receiving these calls several times a day for the past few days and they're really irritating - I haven't answered any of these calls. It's obviously a cold calling sales thing (and a pretty dodgy one too judging by what has been written here.)
However, so persistent are the calls, that next time I get one I'm going to answer it, and give them all my financial details, send them my passport, the keys to my house, and my girlfriend; and then emigrate. - If that doesn't stop them, nothing will.