My son collected for an organization (a Jewish one) and as a reward they gave him a debit card and they by mistake gave him a lot more than he was supposed to get. So my question is does he need to give the extra back or is he allowed to keep it.
(We tried numerous times but nothing ever came of it)
If it is a Jewish organization then he has the mitzva of hashovas aveida, to return their lost money that came about because of this mistake. As long as you informed them that you have their money that is enough. Since it is a debit card, which means that he money is in their bank account until you use it, then you have a simple remedy, he should use only the amount of money that he is owed, and not more than that, and the money will stay in the organizations bank account, and everything is fine. Unless it is a gift card, which is really worth money, then use what is owed to you, and return the card to them, or let them know that you have it.
Hashova Aveida Khilchoso 3-6 in the name of R’ Eliyasiv, and R’ M. Feinstein zt”l.