In a station? Didn't happen to be Warschauerstraße? I had multiple incidents like that there so I ended up just avoiding the area and station altogether. Would purposely take different subway/train lines so I didn't have to be change there. For me it was always just knowing which places to avoid. Time is another big thing, if it's a weekend and there are a lot of drunk people out, taking public transit home alone as a woman is automatically going to be more risky. Especially if there is no one else around but you and the drunk guys.

Also if there is a group of problem people in one car you can get out and change to a different one in the subway or train without anyone thinking you're avoiding them and yelling at you for it. Just prioritize your safety, even if you end up having to take a taxi home.