Toshiba 50UA3E63DT TV Keeps Disconnecting From WiFi

I purchased my Toshiba 50UA3E63DT television about three months ago on May 5 from Pazarama.com and had it delivered to my address in Kütahya. Since the day I received it, I have been experiencing Wi-Fi connection issues. The TV connects to the Wi-Fi network but disconnects after about five minutes and does not reconnect. I have faced this problem repeatedly. I tried all the recommended steps such as restarting the modem and testing different Wi-Fi networks, but none of them worked. I also tried to reach Toshiba customer service but was unsuccessful, only managing to send an email, and I have not received a response yet. My product is still under warranty, and I request a solution to this problem, preferably a product replacement or a refund. I can provide my order and invoice details as photos. Toshiba has been a disappointment; if I had known it was manufactured by Vestel, I would never have purchased it.