while they did say "one of the following days" they paid in the first week in real-time and did not revoke that. so they must have meant to pay in real time until they realized how dumb that is.
yes it does matter when they give it back to you, because it construes differently. if i make clear the day by saying to you "tomorrow, i will give you $10 for every $100 that you lose today", it sounds a lot more like you get the money based on the end balance.
now the hypothetical, i play 4 hands of $100 each at blackjack. i lose two hands and win two. overall i break even. in real time i lost 200 and won 200. am i owed $20 at the end of the day? or did i break even and lose 0, therefore am owed no cashback?
bonus crediting in real time means something different than cashback on losses, it means essentially a 10% comp rate on all losing bets. all winning bets don't earn get cashback but win, and losers only lose 90% of the investment due to the cashback. almost every bet in the casino becomes positive expectation.
what casinomeister is saying is "way to go guys, you clever buggers solved a stupid bonus and i'd love to see you get paid because of their fault, but please realize they were out of their minds to offer it and you shouldn't be surprised they try to whine out of it". i can't blame you all for working it though. they made it up and crafted it to work how it worked, their bad for offering such a deal to the players.
and meister also highlighted the closure of the monthly bonus at interwetten, where they got featured on bonuswh0ring sites and began losing money to savvy players. and likewise they retro-voided the bonus in its final month. so it makes sense that their response is "we don't look into our promotions until we see an overall loss from it". i say roguedom is in order.
players, you had no reason to think anything amiss, as it was playing out strictly how the words said. you have a point that the "following days" ought to have been listed, but strictly speaking "on one of the following days" could means one day following the promotion. but in that case it makes no sense that it was credited the same day, live to your accounts. and truthfully, you had to see it for what it was, and realize this was not the standard cashback offer you'd expect to get from a casino. but i can't fault you for jumping on it, as you would a tenner you find in the parking lot.
i can fault you for even playing there to begin with, but it's possible you didn't know any better. they aren't highest-order crooks (til now) but definitely quite sketch. and one thing i will say is that if you know you were heading there exclusively to wh0re that promo, please don't cry or be bitter if the meister can't get your money back. you're in the right, but life's not fair sometimes. and at least you're martyrs for the cause; once they get rogued it will help people to steer clear, should they stay in business.
i agree with post #2, RIP interwetten, they did a runner and will in all likelihood fold up shop and go launder their assets in bolivia or something.