Buying currency at the rate of delivery date

Q: I transferred 200 dollars to my mother in Sudan in the name of a person who is authorized to receive this money through the bank and deliver it to my mother. However, this person thought that (Part No. 13; Page No. 450) it was his brother who sent him that sum of money, as he had a brother who lived in Saudi Arabia. Accordingly, he went to the bank, received the money without inquiring about the name of the sender, and spent it. At that time, the dollar was equal to 200 piasters, for instance. Twenty days later, I received a letter from my mother in which she asked me why I had not sent her the money. I told her that I had sent it in the name of that person. After making inquiries, we discovered that that person who took the money is the one who received it in Khartoum. Because this issue lasted for more than a month, the price of the dollar changed and became 250 piasters, for instance. There came the disagreement whether the person who received the 200 dollars a month ago is entitled to the rise in the price of the dollar or not.

A: If the case is as you mentioned, that the sum of money was in dollars, and that man received it in the form of dollars, he should return them in the form of dollars, too, or in piaster's with their price on the day of receiving them if it is agreed upon this. He is not entitled to the difference due to changes in the currency value. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.