Not close friend why you lend money to him?
Aiyah really is talk $ hurt friendship sia.
Maybe you want to meet him and talk face-to-face nicley? And
show him the IOU? Liddat u better bring a neutral 3rd party along
(preferably a mutual friend) to calm things down if it ever gets
agitated (Aiyah Money talk everytime end up fight one so better
prepare for it)