Mivi — MIVI classic collar

I purchased MIVI classic collar from flipkart but it stop working on 24.11.2022 so i complaint to MIVI as it is under warranty i mail to the company and they pick the product and after 10 days arond i get my product But sound is not clearly... after neckband repaired voice is not clear only sound i can hear. I connect again in customer care but now they told me it's normal behaviour.
I almost use this product 7 month at that time this issue is not accured. music and sound is very clear but after repaired through service center voice is not clear then how it's natural behaviour.

My complaint no is - 1237295 and they close my case. What the hell is that.

I heard that mivi service is ridiculous but today i face it.