How do contact the Chief Executive of Customer service for a complaint?

Good evening,  I have been a customer of AT&T over 10 years now.  I have had the worst experience with this year with a supposed new Samsung 20 5G phone,  that I ordered over the phone 1 August  2020.  I had never ordered a new phone over the phone and I only did it this time because of COVID-19 and I needed a  new phone for my Real estate career.  The phone had to be replaced 4mth later because of a glitch as the customer service rep said. It started having a heart attack (i.e. screen started flashing,  then went black came back on , locked on me I couldn't  access anything ) while I was enroute to show properties in an unfamiliar rural area. I  called at&t immediately  and the customer representatives explained the issue, the representative stated that was a common issue with the phone and sent another.  I  received the first replacement 27 Dec  2020 a week later that phone did the same thing, this time it was worst. So I took it to At&t store so they could figure out the issue and I could have a witness for the craziness.  They witnessed and called at&t customer care to request a second phone which I received late  January 2021.  Approx. 3 to 5 weeks.   Early March the second phone does the same thing,  once again I take it to at&t store, let them witness,  then I call at&t customer care.  All the while my frustration and stress is building because my phone is my lifeline to my business and its literally taking the life out of my livelihood.  Needless to say I  received a third phone from the warranty department,  and as of 11 June 2021 that 3 rd phone that was sent me restarted for the new updates and never came back on.  It shows the words phone starting across the screen  with a blue line going back and forth  but will not allow me to make calls or access the phone in any  way.  I have constantly call customer service each time with this experience and the one time any of was kind was the first time,  and 15 June when speaking the 2 At&t tech support representative, who told me to send the phone to Samsung so that they can fix it. However,  I have lost all my data, with clients information,  I have to start over, I have lost time, missed appointments. because I was sent a refurbished phone from the very beginning and then I consistently lied too by one of the mangers,  who stated she would look into it, and call me back. She never called. Now I am without a phone for lord knows how long.  So please if you have any information on who I can email,  or write to get some assistance.  If not I will have to cut my losses and move to another service provider.