how to leave a good customer service review?

I was with AT&T so I wanted to switch to a different carrier. I went with T-Mobile. , what a mistake that was. First the IPhone 12 they sold me had problems right after I bought it. They sent me to Apple Store which was a goood drive to get to apple told me that it's a T-Mobile issue so that never got resolved. The sales person told me when I got the phone that I could upgrade in one year That was a high lie. The Apex nc T-Mobile store is the worst store. I'm stuck with. a one that is now worthless. And he told me I get free Netflix. Another lie. I'm putting this out there for others to beware of this apex NC store. I would never anyone to go to T-Mobile. Stay with Verizon or At$t I'm 100% changing  back to AT&T