New phone scam?

Just had a call purporting to be from NatWest Credit Card Services - they were cagey about identifying themselves, and eventually gave me a number I could ring them back on (0870 888 12 46 - which doesn't seem to turn up on Google however I break it up), and seemed surprised that I wouldn't give them any more information until I'd rung the number: they said the number was closed at this time of night. I mean, what is the point of giving me a number I can use to verify that they're not a scammer if it's no actual use? "Nice try, mate [click]".

Anyway, I rang the number and yes, it does say the office is closed, but it gives no information about whose office is closed.

This is either a scam or incredibly bad practice on the part of the bank....

New phone scam?

Just had a call purporting to be from NatWest Credit Card Services - they were cagey about identifying themselves, and eventually gave me a number I could ring them back on (0870 888 12 46 - which doesn't seem to turn up on Google however I break it up), and seemed surprised that I wouldn't give them any more information until I'd rung the number: they said the number was closed at this time of night. I mean, what is the point of giving me a number I can use to verify that they're not a scammer if it's no actual use? "Nice try, mate [click]".

Anyway, I rang the number and yes, it does say the office is closed, but it gives no information about whose office is closed.

This is either a scam or incredibly bad practice on the part of the bank....