fake reviews

Hello, this is my first time writing here and I realize I'm not alone in this. Unfortunately, Amazon does not prevent fake reviews. I send products to the VINE application and get very good feedback. Because my products are really high quality and useful, but powerful competitors are attacking my ads with fake comments. They try to portray user errors as if they are related to the product and the seller. I'm really tired of this. I contacted 3 times about this issue but could not find any support. Feedbacks are always fixed comments. They do not implement practices that protect sellers.

Can someone suggest what I should do about these?