I experienced a possible bug during an Arena Powered Cube game a little while ago. Here's what happened:

Me T1: Land, pass.
Opp T1: Land, pass.
Me T2: Land, pass (holding up Mystical Tutor).
Opp T2: Land, pass. At end step I cast Mystical Tutor, putting Time Walk on top of my library.
Me T3: Before my draw, Time Walk gets milled... And I draw Steel Seraph.

I would go on to lose that game. Is there a way I can get reimbursed?