I played Devil's Delight at Casino Sieger, and I was running pretty well with lots of bonus game souls collected. The rule is, that souls are saved for 48 hours after the last spin. I took a 43-hour break, and when I logged in I saw the 11 or 12 souls disappeared. Being a high roller and playing at 20€ per spin as a frequent player I know theses souls are worth around 1000€ on average in the bonus game.
I contacted Casino Sieger Support, and also NetEnt, and both say that only the other party is able to help, and then both stopped replying to me.
Casino support told me they cannot find any glitch, but I asked them to send me the play logs, as this would prove my point, and they don't.
The same way we players must play by the rules, a casino, and a reputable software provider should do the same. I don't know what happened, and I won't write about some suspicions I have here, but I would really ask to finally look into it.