AITA for not buying my brother and his girlfriend a gift after they didn't pay me for a $1000 car repair?

I'm a 24F. I have a 22M brother. I'm an auto mechanic. My brother and his girlfriend came to visit a few months ago but not before their car broke down. Their timing belt tensioner failed and shredded their timing belt, and then their serpentine belt snapped so they needed both of those replaced. Since I'm a mechanic I did all of the labor for free. They only paid for the parts and tools I purchased for them. After their car was done they stayed at my place for around a month before moving into a new apartment. Now it's Christmas time so I got them stockings. In their stocking I got them some chocolates, a bottle of wine, and a sandwich card. They opened the stockings and gave me a hug and said thanks. <br><br>When I got home from work today there was a note on my fridge from my brother and his girlfriend. It said something along the lines of "How could you be so cold? We got you a $50 Barnes and Noble gift card and you give us chocolate and wine? We spent $1000 on your house, didn't you think that we deserved more than a bottle of wine and a card? It was very disappointing and honestly it hurt a little. See you at Christmas. Love you".<br><br>I feel so confused right now because they didn't spend $1000 on my house. They spent $1000 on their car. I did all of the work for them and I didn't ask for payment because I love them. Does that mean I'm the asshole for not getting them a better gift?