I am a Ph.D. student on a student residence permit in Germany, currently in the middle of my second year (out of three, but the project may be extended).
There's a woman in the laboratory who gradually became more and more aggressive towards me, screaming at me and banging things against the table when I made mistakes. ETA: I have not observed her attacking anyone else, so either she is good at being alone with her victims, or I somehow present a special interest for her.
Around a year ago I tried to have a talk with her; since she doesn't speak English well and my German was only A1 at the moment, I asked my effective supervisor (the laboratory head) to translate, which he did. This seemed to help for a while: we were able to interact in a solidly professional manner for some months. Interaction with her is unavoidable, by the way, since she's responsible for ordering all the chemicals and she knows where everything is stored.
A few days ago the problem returned: she started by making nasty remarks about my underperformance and underattendance and described my experiment as "hopelessly contaminated" (despite my supervisor later agreeing that the levels of contamination were well within acceptable limits). Yesterday she screamed at me for using the wrong kind of qPCR plate, took it from under my hands and threw it in the trash bin despite most of the plate having been taped off (as customarily done in the lab) and available for reuse. When asked why and to stop screaming, she cited lack of time.
My supervisor, when contacted about the incident, told me that he "understands her", since the plates are expensive. I am not handling this well. What should I do?
ETA:
Should I start walking around with dictaphone running? Last time I tried it, we've already had the talk and she stopped attacking me, so I didn't get any useful evidence. My supervisor "knows" that she attacks me, but there is no paper trail. (yet?) And even if I get any evidence, who should I submit it to? My supervisor, again, hoping that he'd understand me this time? Someone higher up the chain? Even then, what should I be hoping for, with that evidence? Getting her fired (which I don't find desirable or expect to be possible in the first place) would certainly be a pyrrhic victory, making my supervisor want to dispose of me -- and he'd find a way.
Should I try to leave the place (as recommended by Sutton, 2017)? As an international student on a residence permit, I can always go home, but that would wreck me psychologically. Is it even possible to change labs for an international student on a government stipend in Germany?