Possible to sue companies for lack of security/support?

Nx has no value u turned ur real money into another form of mesos
Nexon only service to you is providing you with the nx you bought aka paypal error ect
and they do

If I present a receipt that shows I made payment for a service, that they provide, and I lose it because their door was wide open, with proof by the very receipts on the website by what was purchased showing where the nx is, and refuse to compensate it that's a problem.

Virtual property isn't worthless property and what the TOS says isn't by itself solid. They would have to justify it, which would be pretty hard with the resources showing that it was stolen, especially if a list of compromised accounts would have to be provided, and your name at the very top.