Banned for chargebacks

I got banned for chargebacks and I dont even know what that is.
Ive been playing legit for the past week or 2.

When you buy NX, get the NX, then tell Paypal you want the money back.
Nexon IP bans chargebacks I believe.

They can make mistakes, submit a ticket.

This must be a mistake because Ive never purched NX.
Although me paypal is being shared