Poco X7 Shuts Down at 29th Second of Calls - I Want a Refund

I have been experiencing an issue with my Poco X7 phone for about four months. During calls with certain numbers, the phone automatically shuts down at the 29th second. The problem was temporarily fixed but has started again and is still ongoing. So far, I have not had any other technical problems. My phone is under warranty, and I have the warranty certificate. I have not yet contacted the authorized service or customer support. I paid ₺18,000 for the device when I bought it, and I am using it in Gaziantep. I request that this issue be resolved and, if possible, that the product be refunded.