Unless I was specifically expecting a call I refuse to give out ANY information to someone calling me. I've had them say some fairly convincing things and get pushy with threats of service disconnects, etc but that just tells me it's even less legit. I know the numbers of all accounts I hold and I will contact THEM if there's a problem.
I get a fair few scam phone calls every week. Some just get the hang up and some I torment by wasting their time. I get one where people with very thick accents try to tell me I have a computer virus. (and they can tell this from my phone number... how?) I let them blab and then I ask them to get specific and of course they can't be. They hedge their bets by saying Windows, which of course is extra amusing since I haven't even touched that OS in years. When they know they haven't got a sucker, they hang up themselves. I feel bad for old people who get calls like this because you know they are probably clueless about it all.
TL;DR - Don't take the bait. Never give out your information, no matter how trivial, to someone calling you.