Amazon ASIN delisted due to highjacker

Hi,

we just had our ASIN delisted from Amazon and all the resellers were removed, including us, the official Brand.

We are trying to solve the issue with Amazon, but they are not very supportive and it is like they are always trying not to solve the issue, and keep requesting more and more documents. feels like it will not reach an end, and their response is always a copy and paste.

But my biggest concern is that they do not inform who reported the ASIN. How can I find out, and what is the best way to solve this situation with Amazon? Any idea?

Thank you!