"only XL-3"

Here's the situation: apparently, they started playing with Alin, drew a template, negotiated about castles and colors, and he refused to play, writing:
TsuAlin Apr 29 at 12:20
"we go other time, i dont undertand the rule then". Previously, I wrote about the rules and asked him to read them. I wrote that he hadn't played a single game in this tournament and wasn't pretending to be stupid. In response, he started insulting my parents. And he left to play a regular game. What should I do with this guy?