If you're one of the unlucky few who has been afflicted by an issue preventing you from getting past 499 wins with a class, there's an easy fix for your frustrations.
Aelathera, from Blizzard's Quality Assurance team, asked those with the problem to check and see if they had pending arena rewards. It turns out, that's the issue! Go into the Arena game mode in your client and gather your rewards.
For those that are still affected, could you enter into Arena and make sure there is no reward pending on that screen then try to get that 500th win?
Disguised Toast Can't Get Golden Warrior
The above issue happened on stream to Disguised Toast recently. Here's his reaction to it and then some gameplay of a Gunspire Warrior deck. Thanks for the great thumbnail, Toast!