Credit Card opened in my name.

I was looking through my account on Credit Karma and I noticed there was a new “Credit One” credit card opened that I didn’t recognize. I noticed an address in Virginia was added to my report too. I call the fraud department credit karma has listed on the company to report it. The lady that helped me wanted my Social Security number so she could look into my account. After some back and forth about why they needed my social and couldn’t do it through my name and date of birth, and me googling Credit One and matching the number I called to the number on the site, I finally gave it to her. She said someone had opened it in Virginia and that there was $400 charged to it. Then she reads me back my correct address and tells me the card is maxed out and that the limit was $2,000. Then a few seconds later she tells me the accounts been closed since last month and is already under investigation with their fraud department and no further action was needed on my part. What do I do? Dispute it with transition and equifax? Or wait it out and let it drop off by itself.