Well with all the maintenance cycles going on and downtimes extending to infinity, the EXP buffs are kinda paltry at this point. Adding up lost play time, you're going to break even in gains versus downtime.
It would have been worse if it was now items exploding at ungodly levels off of monsters. That would have required a rollback of some level. Be glad it was only exp.
If Arwoo said it ain't happening, then it ain't and you spent 20k NX on a gamble, and lost. That's the consequence of gambling, you might actually lose.