Salam lovely sister,
If you have examined holy book carefuly, you will see that for every punishment prescribed, it is stressed out that if an evil is commited unknowingly (you dont know it is forbidden) or unintentionally/accidentaly, God doesnt account it as a sin
he only accounts as a sin when you know what youre doing, and you still choose to do it. To be responsible for something, you must have been aware of what youre doing, otherwise that person has no idea what hes beeing accounted for, right?
See this verse:
006.054
"When those come to thee who believe in Our signs, Say: "Peace be on you: Your Lord has inscribed for Himself (the rule of) mercy (Arabic: Kataba ala nafsihi): surely, if any of you did evil in ignorance, and thereafter repented, and amends (his conduct), lo! He is Oft-forgiving, Most Merciful"
017:15
"Whoever goes right, then he goes right only for the benefit of his ownself. And whoever goes astray, then he goes astray to his own loss. No one laden with burdens can bear another's burden. And We never punish until We have sent a Messenger (to give warning)."
I guess these are enough to form the opinion that God never punished people if a warning didnt reach them. They were only considered guilty if they received clear warning and refused it.
God bless
Seraphina