The few people I've seen say got their fix did indeed confirm they're just refunding you the lost experience points instead of levels themselves, so I wouldn't expect much beyond that. There's not really any way to compensate you for what you would have been able to do, short of maybe providing a day of game time or something similar. I'm still waiting on them to refund my level, but I'm just going to sit it out until they actually figure out the bug causing this.