Vewlix F monitor problem

I bought a Vewlix L cabinet from I had a monitor problem. After two years of negotiation, I swapped it for a Vewlix F and paid extra to make up for the price difference.

The Vewlix F monitor has severely weakened backlight. Here are some photos:

I asked the seller to replace the unit for another one that doesn’t have this problem. He told me that he will check out his other Vewlix F cabinets and give me a better screen. Then it went silent again. After many weeks, I e-mailed and he told me that all his Vewlix F monitors look like this. Meanwhile, 3.7 years have passed by and I still don’t have a decent screen. I asked the dealer if he has new Vewlix F stock. He replied that he doesn’t allow me to swap it. So I paid $2600 for a Vewlix F cabinet with backlight that’s about to quit. I sent these screenshots to the seller. He doesn’t acknowledge that the screen quality is unacceptable.

Where can I buy an affordable replacement Sanwa screen for my Vewlix F?

Some models of monitors and Tvs do have some poor backlight coverage and in the industry unfortunately this isn’t considered damage or a manufacturing defect.
Like how a stuck pixle isn’t covered in most warranties.

I go back and research on this if this is a common issue on the Vewlix F monitor or not.