played book of dead for promo and later got told it was excluded provider

so i went for a slot promo and naturally picked book of dead since it's my old comfort pick, spun through the whole bonus, and then only later did i get a message saying "oh, sorry, that's an excluded provider." didn't see it in the terms at all, or maybe it was buried somewhere, but there was nothing flagged when i started. i'm used to more transparency from poker or live tables, so this feels weird. do they just not code it so you can't play excluded games? i get if people try to stretch promos, but if the system lets you play and doesn't flag it, feels like a trap. just trying to figure out if this is standard, or if others have gotten burned on similar slot exclusions or stealthy terms. i'm thinking next time i might skip these promos altogether unless it’s super clear.