Account breached, games purchased?

Hi all, I just woke up and checked my email to find that a free add-on and a $59.99 game were purchased by my account, but obviously I did not purchase them myself. The game is called Fortnite? And the add-on was a Dead or Alive thing which I do not have.

A quick search of the Sony/PSN website hasn't been much help, and I'd really like to know what my recourse is here.

Thanks anyone who can help.