Samsung Note 20 Unltra 5G a horrible expensive piece of junk

I bought a Galaxy S20 Note 5G Ultra on contract on 3 Dec 20 through Vodacom Shop Fourways Mall and it re starts itself. When it's quiet I must chec, because it is restarting. I go to sumsung Members where it tells me about the error and request me to send report, which I have done hundreds of times. I sent the phone in for repairs at Fourways and 3 time now, I'm told they don't pick up any problems, I have shown them the error message I keep reporting to Samsung and still they return it. I pay a lot of money for this phone that is causing me so much frustration and today I am told they will not exchange it for a working phone, it's all I want, a working phone.