Samsung M51's Recurring Issues and Unexpected Charges

I had to send my Samsung M51 phone to the service because I couldn't make calls or use the internet without Wi-Fi. When they gave me back the phone, they told me that both the motherboard and charging socket were broken and asked for 4,000 TL to fix them. What confuses me is that this issue happened again within the first month of buying it, and they had fixed it once already. Why do I have to pay 4,000 liras for the same problem? It's really frustrating to keep dealing with these same issues on a Samsung phone. It makes me worry about how reliable the brand is. My old phone also crashed out of nowhere. What's happening with these devices? Does Samsung have anyone who is willing to support their products?