I was told someone may have hacked into Apple Pay and use my Costco Citi credit card

I just removed all of my credit cards from Apple Pay. Someone, I am told, may have been able to hack into Apple Pay and use my Costco Citi credit card to charge items. Ciiti informed me last month that someone used my credit card in AZ. Now they are using my card from CA. I was told they have really racked up the charges on my now canceled card. I have had to now change out this credit card 3 times in less than 2 months.

BE CAREFUL.

[Re-Titled by Moderator]