Redmi 11 Pro's Network Problems Persisted Even After a Swap

I bought a Redmi 11 Pro phone, but because of problems with the network, I had to send it in for repair. After about 10 days, they couldn't fix it, so they got a better model to replace it. But the problems are still there on the new phone they sent me. During calls, the other person can't hear my voice, and the internet is always giving me trouble. The phone often freezes up, gets hot, and keeps asking for updates. I paid a lot for this phone, and it was brand new and came with a warranty. Please do what needs to be done to solve these problems. You have sent me two broken phones in a row. If you can't fix this, I want my money back.