As a general rule, I don't answer phone calls on my cell phone from numbers I don't recognize. If it's important enough, whoever is calling will leave a message anyway. I keep pretty close tabs on who gets to have my number.
Today, I got a call from an unrecognized number. The area code is an overlay that could be anywhere in the province of Alberta. Whoever called, did leave a voice message. Basically, it said
This is so-and-so from [a well known international company, that I've never done business with], calling for [my real name]. This is about a fee that you've been charged, probably in the amount of $7.56. yada, yada, yada. Please call me back at [a toll-free number] and I will send you a cheque to compensate for the charge.
It strains credulity to believe that this company I've never done business has charged me "probably" $7.56 for some unknown reason. Probably? You don't know? And if they really did, they should be able to credit it back. Oh right, they could send a cheque, if I gave them my mailing address. Uh huh. If they made a legitimate mistake, they wouldn't need my permission to correct it, or my address, or anything else that they should already know.
So I'm guessing it's a phishing expedition. I have no intention to call them back to confirm or deny anything.
More oddity: the last 4 digits of the phone number I'm requested to call back are the same last 4 as the number that called me, but the area code and exchange are different. And, more intriguing, yesterday I received 2 calls that I also did not answer, but no message was left. Those 2 calls were from my area code, but a different exchange. Funny how 3 different phone numbers, from apparently 3 different locations, all have the same last 4 digits. A curiosity.
I'm writing this as general advice: Be careful who you give information to, if you don't know who they are and why they are asking.