When we first moved here, our Visa card had been compromised. Thankfully that isn't the one I have memorized
Whenever I have had a call from a cc company, I always say I will call you back so I can call AMX/Visa and check or I ask them to give me the info that they are always asking for when I call.
Normally, the cc companies catch the fraudulent charges but with the "legal forms" there was a repeat for over seven months and I caught it because I finally asked my husband..grrr. They can be sneaky.