Dear respected Muftis,
Salam alaikum was rahmatullahi was barakatuh,
This question is asked on behalf of my friend. My friend told me that he once stole KitKat (chocolate) from a supermarket. He is very sorry and wants to find a solution for his sin. Also, he really does not remember how much he stole, but the least was that he stole only 1 KitKit. But, he says “maybe” three of four quantity. So, what should he do? I mean, he cannot return the chocolate, since he ate them all. Also, he does not remember when he stole and who much was the price of one KitKat. So, should he take the price of today market’s Kitkat and assume that he stole 4 quantity (maximum possible assumption, according to his brain/memory) and just pay that price to the manager of the supermarket? After that, will he be forgiven by Allah?
Please reply as soon as possible.
Jazak Allah khair! 
May Allah reward us all the highest level of paradise.