If the CC company rep told you the authorization was valid for each of those transactions, it is very, very likely that your account was compromised and someone else put in the other authorizations, besides yours BNS Gold. Unless of course, you put in 20x authorizations yourself, which you state you didn’t.
I strongly recommend using 2-step verification on both your NCSOFT account and your email account. If your bank entity allows you to use 2-step, use it there, too.

We live in a digital age.
You have to protect your digital transactions and identity as much as you can.

I am a little surprised at the CC company rep’s response, though.
Him verifying the authorizations is normal. But typically what happens, is that they lock your account immediately (You don’t have a choice; they just lock it, period). Then they refund the most recent transactions and lastly they conduct an investigation that can take 1-2 weeks.

Yes, I worked in this field for a little while some time back. Normally, you, the consumer, does not have any responsibility if there is fraud in R4PG BNS Gold Store, unless it is proven that you had a direct involvement after the investigation is over. In which case, it’s pretty bad for you. Fines and potential jailtime, etc.

I’m surprised AMEX didn’t simply dispute them right off the bat. Also, the fact that you don’t monitor your own CC transaction history. Also, that you don’t use Paypal. And in case you haven’t set one up yet, a 2-step verification does have its merits despite the possible downsides.

Anyway, good luck with that dispute. I hope you get your money back but it’s not unlikely that your account was compromised Blade And Soul Items. And it helps to have multiple CCs with lower budget caps instead of having $3000 limit on one.