Eden equipments quest bug

Hello,
i got a bug that make me unable to complete a equipment quest from Blacksmith Thorn, and got "extra/doubled" equipment from him.
List doubled equipment i got from him :[list]
[*][url="http://irowiki.org/wiki/Eden_Group_Equipments_Quests#Weapons_by_Classes"]Weapon III[/url]
[*][img]http://db.irowiki.org/image/item/18514.png[/img][url="http://db.irowiki.org/db/item-info/18514/"]Eden Group Hat II[/url]
[*][img]http://db.irowiki.org/image/item/15031.png[/img][url="http://db.irowiki.org/db/item-info/15031/"]Eden Group Armor[/url]
[*][img]http://db.irowiki.org/image/item/2571.png[/img][url="http://db.irowiki.org/db/item-info/2571/"]Eden Group Manteau II[/url]
[*][img]http://db.irowiki.org/image/item/2473.png[/img][url="http://db.irowiki.org/db/item-info/2473/"]Eden Group Boots IV[/url]
[/list]
I don't know where this bug start, but this was my steps :
1. Complete level 70 - 79 quest, talk to UR and then talk to Thorn to get new equipment

2. Talk to Thorn to get armors and weapons ,

3. Talk to him again to get enchantment, he gave quest (easy)

3. I complete it and he gave the enchantment (Cooldown)

4. Complete level 80 - 89 quest, talk to UR and then talk to Thorn to get extra enchantment

5. (Cooldown over) talk to Thorn and he gave quest (easy)

6. Complete level 90 - 99 quest, talk to UR and then talk to Thorn to get another enhanment

7. (Cooldown over) , talk to Thorn with required items (iron ores and irons), but he gave me another quest (hard) - collecting used iron plate, and i unable to complete the "easy" quest,

8. Gave him the items, then he give me the extra equipments i mentioned above.


Reference:
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[img]http://s9.postimg.org/ndu6ddcvj/screen_Hercules000.jpg[/img]
[/spoiler]
[url="http://irowiki.org/wiki/Eden_Group_Equipments_Quests"]http://irowiki.org/wiki/Eden_Group_Equipments_Quests[/url]