ban for smurfing

Hello, my account was blocked for smurfing. That day, I went to a friend's house where we decided to play a game together on my account on his computer. We live about 500 meters apart. A day later, I learned that my account was blocked for smurfing, and my friend's account was blocked for playing on a smurf. Even though we're different people, we have about 10 games in the same party. Support is sending ready-made answers and is ready to provide any evidence you request. Please help me understand this situation.

My account is timonX, my friend's account is Lookslikek1d.

Ticket #13920301