Don't hang up when you hear it's the court, because even if you don't answer the phone, the court will issue a subpoena. At this time, calm yourself down and ask which court, which court, which judge and the contact number of the judge. For example, the judge told you that someone sued you for trademark infringement and the Shanghai Changning District Court accepted it. This may be an infringement on the platform of Pinduoduo, so you should be prepared in advance.
Remember the name and telephone number of the judge so that you can contact the judge later.