iPhone 8 issues and terrible Apple support

I have tons of issues with my iPhone 8 bought a year ago. First my phone wouldn’t connect to data and I had trouble making and receiving calls, went to the Apple store they tied trouble shooting and then ended up giving another iPhone 8. About a month later began having issues with connecting to wi-fii and couldn’t connect at all to wii-fi. Called someone who did some trouble shooting over the phone and the issue got temporarily resolved.

now the same wi-fi issue is happening along with my phone keep shutting off on it own. Just today it disconnected me from the call and then shut off and couldn’t turn back on until 3 hours later when battery was all drenched out and was attached to charging adopter.

Spoke with Adam and others, and they were absolutely not helpful. Opinions, suggestions? I’m a huge Apple fan but this experience has been terrible and I’m deeply disappointed.