Somehow an incompete new version of @BanWarnBot got deployed.
This means also a first part of translation effort accidentially made it into the bot, causing bad texts somewhere.
Currently it uses the user's language. Later a per-chat switch will be there, allowing to choose a fixed language (e.g. English) or auto (language the user's client sends us) for that chat.
I will fix that in the evening, after work.