Almost certainly a scam call. When I came up with a search saying that it wasn't valid I did try calling the number - thinking possibly it might have been from somebody in Sydney that I don't have on my contact list- the number was was not available

Caller: Visa scammers

I don't even own a visa card. They didn't address me.by my name, just that there was a problem with my visa card. Typical 3rd world scammer. Idiots.