Vivo V29 Lite Call Noise Issue Not Fixed After Multiple Repairs

I have been using my Vivo V29 Lite for 1.5 years, and I have had sound issues from the very first day. During calls, the other person hears siren-like noises, and my voice cuts out. I bought the phone from Media Markt, and under warranty I sent it to KVK service a total of six times, and once to Vivo’s own service center. After the first submission, my phone was replaced with a new one, but I continued to experience the same problem with the new device as well. Every time, I was told “there is no issue,” and the device was sent back to me. However, I have video recordings clearly showing the problem, and I’ve heard from other users that similar issues occur with this model series.

Throughout this entire process, my issue has not been resolved, and the problem still continues. For this reason, I am requesting either an exchange for a higher-end model or a full refund.