How to turn in Contribution Points

[Ryufu]

So I've been doing some faction stuff and slaying enemies of opposing faction, but once I hit 100 contribution it suddenly stopped? What's with that?

 

Also, I don't get how to turn in my points. I talk to the exchange person and all she does is tell me how, but doesn't DO it. She doesn't give me the option.

I'm wearing my outfit, I have exactly 100 points and I'm talking to the faction exchange person.

 

Edit: I also understand that I don't have prestige points yet, but I exchange contribution for them. I killed players, mobs, and special mobs, and the exchange person says unable to exchange.

[CorrosionWhite]

You seem to be slightly confused I think.  You exchange prestige points for contribution points, not the other way around. You get contribution points from faction quests and exchanging prestige points.  If you die or remove your faction uniform while you have prestige points you'll lose them and have nothing to exchange.