Baseus Encok Wm01 Headphones' Lead Levels Exceed Safety Standards

I bought a pair of Baseus Encok Wm01 headphones a year ago. I've been using them 5-6 times a week for a few hours at a time, so I wouldn't say I'm an excessive user.

A few weeks ago, I started getting headaches every time I wore the headphones. I also noticed a small lump forming under my ear. I didn't think much of it at first, but then I read the user manual and saw that the headphones contain lead.
The amount of lead in the headphones is higher than the safety standards set by the World Health Organization. Lead is a toxic metal that can cause a variety of health problems, including headaches, fatigue, and learning disabilities.

I'm concerned about the health risks associated with these headphones. I'm also disappointed that Baseus would sell a product that contains lead.
I've contacted Baseus customer service and asked for a refund. They've refused to give me a refund, saying that the headphones are within the safety standards.
I'm not sure what to do next.