MTS is erasing my items.

Speaking of which, I know Nexon keeps changing their ToS. Does that mean Nexon's ToS and EULA is invalid, due to it being different from the one you originally agreed to?

The bolded isn't true, it's applied when you charge the NX. That's why you can still go to the store and ask for a refund, but if you already charged the money and you refund it at the store, then they'll bounce back and Nexon can ban your account. What if you try charging and the money that was supposed to be there got rolled back (then it's technically not NX)?

What if you spend it from PayPal (in which Nexon withdraws from the PayPal but your cash items get rolled back)?

You also agree that nexon has the right to change their agreement and you are forced to follow the changes.

and if you buy anything from a store, you are still not messing with the store itself. they dont sell you the NX, they sell you the plastic pieces with ink on them. no matter how you buy the cash, nexon are responsible for it, and you agreed that they can steal your nx.