I realize that this bug has been posted before, but I'm adding more information.

Platform: Windows
ISP: AT&T UVerse
Type of Internet Connection: Cable
Internet Connection Speed: 50 mbps
Date & Time: 12/18/2016 at around 11:00PM ~ 1:00AM EST
Frequency: Always replicable
Character Name: Prothescar
Race: Hume
World: Valefor
Main Job: RUN
Support Job: SAM
Area and Coordinates: Reisenjima Ingress #10 (Omen Lobby)
Party or Solo: Party/Solo
NPC Name: Coelestrox
Monster Name: None
Steps:
1. Receive at least one Paragon rune fencer card

2. Trade the card(s) to Coelestrox. I was trading them in for a piece of armor while lacking some components, so he did not take the cards.

3. Talk to Coelestrox. After speaking to the NPC once again to determine which item I was missing, I discovered that I had double the amount of cards in my inventory than I had previously.

Additional Information: This bug is replicable 100% of the time, but only with Rune Fencer paragon cards. I have attempted to contact a GM several times over the last 24 hours in order to resolve this issue (and have them remove the suspect cards from my inventory), but I have not heard back from one yet. This matter is clearly urgent and should be fixed as soon as possible. I would also like to know what steps I should take to ensure that the duplicated cards are confirmed destroyed to avoid action on my account for a glitch that I have no control over.