Beta Neutral in classic EQ did not have any way to raise once you were less than apprehensive. GMs would reset the faction for players that needed it for important quests, because it was a bug to be able to kill an NPC and have it lowered.
Sources:
http://eqbeastiary.allakhazam.com/fa...ml?faction=131
The "Beta Neutral faction" quest was a money sink for the Incandescent Gloves to get your beta neutral up from Indifferent to Amiable, not a way to fix it if you were dubious or below.
Source:
http://everquest.allakhazam.com/db/quest.html?quest=699
On a side note, looks like you give Mirzna 50 gold to get a Rune of Fortune, you don't vend it off her.