No credit card company will ever take adverse action because you insisted on calling the number on the back of your card. Some companies will call to verify large purchases, but they will never give you guff if you insist on calling them back.

If you ever get a call claiming to be from your credit card company, hang up and call the number on the back of the card. (Not the phone number some guy in a boiler room in Bratislava is giving you.)