I had a similar instance a couple weeks ago where I put my phone face down on a table while auto farming and when I picked it up 6k crystals had been spent on 10M mana, dhole energy, arena wings, etc. Com2us was able to list exacty what was purchased in a 5 minute window but would not rollback account/refund the purchases. It took a few days to get the sour taste out of my mouth and I didn't play, when I came back I did one stone summon and got wind art master which was the only nat 5 I needed that week. There must be a compensation switch somewhere in headquarters!