“How do I ensure all accounts are closed and no further charges are made to my card?”
Every credit card is susceptible to fraud. The least secure method is swiping your card and especially handing it to someone and they swipe it away from you sight. so never swipe you card if at all possible or insert into an ATM.
Inserting the chip, is almost as bad as swiping, offers a slight bit more protection. Tap-To-Pay including Apple Pay and Google Pay are the most secure way to complete transactions. Your personal and account details are encrypted, and even if somehow copied by scammers, it’s encrypted and only your bank has the key.
So, if you swipe or insert chip, you’re exposing your personal and financial information to scammers. Be extra careful and examine your credit card statements every month.