Why FD refund FDL bought yesterday? They didn't use it then? They didn't have money or what? Thats the main problem I see.
What problem? FDev or (in-game) the NPCs decided to give players who bought the FDL a rebate. Just like frequent flyer miles or customer loyalty points from your local car dealership. It was their choice.
You sold some bananas (data) yesterday. Bananas cost $1 yesterday. Today Bananas cost $2. Everyone (NPCs) that bought a banana from you yesterday isn't going to give you an extra dollar for yesterday's banana just because the price went up today.