I've tried to contact support about this, however they are unwilling to help and told me to go on the forums so that maybe a dev can see this and get my item back for me.
To me it seemed like it would of been easy for them to just go in, verify that I did get the book and tried to use it on the server side, and after seeing it's not getting applied could of just tried giving me the item to use again to see if it would work this time. Instead it looks like I'd have to grind it all out to get something that I had already worked on.
Character: Mr Tus
Server: Excalibur
Date of occurance: 9-12-15
I bought the mining folklore for Coerthas, used it, message appeared saying that it had been added.
No new entries for coerthas have appeared under the folklore section of the gathering log.
New entries for the other folklore books I've used do show up. So it's acting like coerthas entry was never added.
I checked the log data dumps in the character folder to confirm that I did buy, and use the folklore tome.
Here's a section of the dump log concerning the purchase, and use of the book.
::'ÿLiana AthlikirLiana Athlikir'Ïÿ invites you to a party.ÐfV°
::You lose the effect of Sprint.ÐfV9
::You join 'ÿLiana AthlikirLiana Athlikir'Ïÿ's party.ÑfV9
::You obtain a þÿóóó'ò/Îþÿÿ{î‚»ì)êtome of geological folklore - Coerthas
:Mr Tus:þÿóóó'ò/Îþÿÿ{î‚»ìTome of Geological Folklore - Coerthas'Ïÿì got mah second book now&gV
:Mr Tus:7 to go'gV
::You ready a þÿóóó'ò/Îþÿÿ{î‚»ì)êtome of geological folklore - Coerthas'Ïÿì.-gV
::A page on Coerthan mining folklore has been added to your gathering log..gV
The only timestamp I have is when the log was last written : Monday, October 12, 2015, 10:13:52 PM Eastern Time.
So sometime before that last write time is when I got the book. I'm hoping that helps with tracking it down on the server side. I also included that I was joined into a party before I purchased/used the book in case that helps track down the time period even more. Because spending time to grind out the same book again would be very discouraging, even more so since there appears to be evidence that I did get it - however it didn't seem to get applied properly, and there are still more books that I need to go after and get.