Idk if you should do it in the book, but I would hand write it out in a note book, full dates and times and exact quotes if you can if what was said, who was there, did customers hear it? Who was shift lead, and get your fellow partners to do the same. Be as specific as you can. And contact your dm if this continues. If you feel uncomfortable/ bullied out of writing it in the dirf express this in the note book. Take pictures of what you right, make copies to give your dm keep the originals.