You can defend your rights or ruin his reputation. This kind of guzheng shop is a cancer in the field of guzheng. Maybe they didn't even have a shop, so they started selling it. I guess there are no serious shops like theirs. To buy a guzheng, it is recommended to go to a regular store, preferably a physical store, or check online to see if there are any big dealers. Don't believe that something in WeChat business is unreliable. Everyone can create WeChat, so you can't trust it too much.

I hope it helps you.