My wife and I have been answering these calls for months. We get on average about 3 or 4 a day, then there'll be a break then it starts again. We even now recognise the pause upon answering before the recording starts, at that point we hang up. If it wasn't for the fact that our number is changing next Saturday when we move I would speak to BT. The calls vary from credit charges to the cards themselves or the payment protection charges. We even had one telling us about bankruptcy, and morgage payments. Whatever info is out there about myself and my wife isn't all correct, we rent our property, and have no store or credit cards.
On the rare occasions I bother to answer those wretched "out of area" nuisance calls I give them a blast from my sound effects library: "26 month old girl - unhappy in cot (early morning)" is I hope a very unwelcoming sound; if not there's always "telephone - constant ring" to entertain them with.