What Credit Crunch?

Apparently there is a credit crunch, where banks are being more cautious about who they lend money to.

Now, they know that I have a 5x salary mortgage and I owe £XX000 on credit cards which I can not pay off at present.

So why have I just been issued with a new credit card that I didn’t even apply for with a credit limit for a further £5000?

And why has the overdraft limit on my current account been doubled without me asking?

Is it down to me to say "no!" to these people, or should I just spend, spend, spend?