Help! My listing has a hijacker.

I have a Chinese hijacker on one of my listings selling the product at a reduced rate and they have stolen the buy box. I’m losing a lot of sales and have tried various methods to remove the hijacker without any luck.

I’ve tried contacting the hijacker, reporting it to Amazon through brand registry and doing a test buy (I’m still waiting to receive the product because the shipping is very slow). I’ve had no luck with anything. I’m disappointed with how little amazon helps.

Does anyone know if there is anything else I can try or is this the end of this product for me.