I received a call and voicemail message from a company claiming to be the company that has my MasterCard account. They said that there may be an unauthorized charge on my account and I should call them back to verify. When I called, it was an automated service and told me there was a $500 charge made this date at an "electronics store". They forwarded me to a customer services rep who wanted me to verify my card number. Instead, I asked what company he was with; he said Barclays, which is not who my card is with. I hung up and called the number on the back of my credit card, and as I thought, there have been no fraudulent charges made with my card. This company tried to sound very professional, and I’m afraid that people may be taken advantage of.