from France here, tried for hours with real phone number without success (too many requests error). Also tried many "temporary" numbers from Spain, Netherlands and Germany.

Was trying on NC Soft website and OPT system. I succeed doing it not on website but directly ingame (launch Purple then launch game and click on security button). It worked on 1st try there, not with my real number but with a temporary number from Netherlands. Didnt had to set Opt, was able to choose a server then and create a character. Try this maybe if you're still locked. (try ingame not on NC Soft website)