Merck Process Development Engineer interview questions

The interview was held in german only even though the job requires both german and english. Even though it was obvious that I was struggling because of the language I was treated as if I am stupid. At the end I brought it that english would have been better. The interviewer told me he knows but german is very important and that I need to understand dialects also. I can not help but see this is racist and not professional. A few weeks later I sent an email asking for feedack and I was ghosted!!