UNKNOWN CHARGE

Hello~ Is this just showing up on your debit card and not a viewable charge on your device? Click on below to check…

Subscriptions and Billing - Official Apple Support

If it is just on your debit card …you did the correct thing because your card has been breached and in the hands of a fraudulent user.

~Katana-San~

I would suspect it being a fraudulent charge as well. You did the right thing by contacting the fraud department for your card and hopefully they cancelled it and are issuing a new card.

Card skimmers are commonly installed on POS terminals that will read your card numbers when you slide it and many times they also install cameras to read your PIN number. Many of these are found at gas stations, ATM machines and even retail locations. From the details you have given, it appears your card has been compromised.