Lost all NX after changing ign

Hello,

I changed my ign today and when I went into my cash shop, I lost all of my NX (nexon game card cash). I had ~10-11k worth of NX? I was wondering how I can get it all back?

Thanks!

 

For your reading

 

oops, thought it was 10,000 mesos. makes a lot of sense, thanks xD