This is what you can see from Wildstar official forums about the recently found bug:
We have become aware of an issue where some players who have attempted to purchase the Advanced Riding Skill have been charged but not received the upgrade to their mount prowess (some players reported losing up to three times the cost, due to receiving three errors).
If you are reaching level 40 please do not purchase this skill until we update this thread that the bug has been fixed.
Our team are working to investigate and fix. Any player who has been affected will have the gold cost refunded to them.
Thanks for your understanding with this issue!
Yes, many players who have reached level 40 reported the same issue. They enjoyed most of the parts in Wildstar, though frustratingly, but it’s really frustrated that when he went to purchase his Advanced Riding Skill with a certain mount of wildstar gold, but did not get the update. Even worse if he tried again but still nothing. That’s several Platinum lost! How upset one could be at this moment.
Surely you will get your refund, but this bug hasn’t been fixed yet. Anyone who is accessible to this update should not purchase it until the official site has given latest information.
There once was the mount boost issue. The fact is any MMO needs its players’ help to make the game even better. So if you happen to find something wrong with it, report to Carbine immediately.
On the other hand, Addons make Wildstar a lot easier and more enjoyable. Addons are effective aids helping players especially newbies to find out the exact position where they are, where the chests are and many others that can make the game much more easier to play. Using them (but not too much, or the fluency will be affected) can solve many problems you will meet when playing the game. Let’s see what are the best addons for Wildstar.
(Note: Don’t be too dependant on them!)
Amp Purchased : Show what amps you’ve unlocked.
AuraMastery: Help place spell and ability CD tracking timers anywhere and pop-up notifications of certain events, IE debuff warnings.
BijiPlates: Better nameplates.
ClassicQuestDialog/ BetterQuestLog: Change the chat bubbles which is kind of confusing.
GalaxyMeter: Combat metrics (DPS and HPS meters)
Galaxy Library: See every item in the game, look at stats, ect.
GatherBuddy: Show you all nearby gathering resources.
IconLoot: Better loot notification.
JunkIt /Ern’s Junk Repair: Automatically repair armor and sell junk items.
NavMate: Square minimap, coordinates and clock and more.
ProtoMail: Mail fetching automation.
SCastBar: Moveable, resizable cast bars for everything.
StickyHintArrow: Increase the quest helper arrow time without having to click the objective every 5 seconds.
RestXPReminder: Give you a warning if you’re not logging out in your house, to ensure maximum Rested EXP.
All addons can be found on WS Curse or using the Curse client. Wildstar launch is on the way. Hope with these addons, you can do excellent in the game.
– Source from:http://www.wildstarplatinums.com/news/wildstar-bug-on-advanced-riding-skill.html