What do you think about this situation?

This is honestly a nightmare.
I bought a hair product from Rossmann. When the dispenser stopped working, I opened the container… and found a decomposing dead body inside – most likely an insect (but I have no idea what exactly it is).
I’m completely shocked. I had been using this product for several weeks without knowing what was inside. I already washed most of that “thing” away.
I emailed the manufacturer on April 4th, but still haven’t received any response.
Please be careful and check your products.
Does anyone know where I can report something like this in Poland or how to best handle this situation?