[Filament]

I've got a serial number from a Philips TV which is manufactured January 2020. What would be the best way to succeed this SE without sending something back?
Claiming that it catched fire? Or leaked some toxic stuff?

Toxic leak is usually from batteries.
Pulling a few strings here, I'm sure this can be improved vastly, but you can go with a blown capacitor. Say it was giving a hissing sound, then a sudden pop and smoke. Courier wouldn't deliver it because they deemed it as a dangerous good, as per https://www.ups.com/us/en/help-center/pa...items.page.
Maybe you saw brown liquid leaking at the bottom.