Dear Blizzard,
There seems to be a bug in the new quest and reward system.
I had 3 parallel daily quests to play 3 games as a mage. 2 of them were at 1/3, one of them at 0/3 and I needed like 60 more experience points to reach the lv. 19 reward on the rewards track. I played one game with a mage in the arena, and got the notification, that I reached lv 19, and need 2800 exp to reach the lv 20 reward. I still had all the 3 quests active, so I played 2 more arena games to complete them. After completing the 3 quests, I checked the rewards track, and recognised that I only got 2000 experience points instead of 3000 (3*1000).
The same thing happend to me a few days ago, when I completed 2 1000 exp daily quests parallelly, but only got 1000 exp for them.
Please check if you can find and correct this bug!