الجواب حامدا و مصلیا
The balance that has been loaded in someone else’s cellphone by mistake falls under the law of “Luqta”. If the balance can be transferred back and there is still time given by the company in which the transfer can be undone, then the questioner should wait; maybe the person who transferred the balance might call him and he can send him back the amount. If despite of waiting, the owner of the amount does not contact the questioner, then the questioner should give this amount in balance or the amount of money equal to it in charity to someone who is eligible to receive Zakat on behalf of the owner. If the questioner himself is eligible to receive Zakat then he can make use of it. However, if the questioner would ever encounter the actual owner of the balance, he will be responsible for returning the amount to him.
And Allah knows best.
