Shockingly poor customer service - No response - Ignore any queries on all platforms claimed as 'contacts'

Bought a necklace for my partner Apr2025. They claim that the necklace is "Premium Stainless Steel" - Durable and resistant to tarnishing" Silver - Classic stainless steel with polished finish" and will not change colour. After a few months - colour changed and I have trying to get in touch with them via the contact link on the website X 3, via email - with no response, via WhatsApp with the link provided on the website - yet it's still unread and NOBODY from "customer services" come back to you or even respond in any way. I provided Photos of the product and the proof of purchase etc.