My iPhone X keeps dropping AT&T network my bill is enormous and I have begged for help

I have had AT&T for years and I was told that my bill would only be about $100 including the cost of the iPhone X! I was told that this is the best phone with the best reception! I am disabled and on a fixed income. My network keeps disappearing! I can’t make phone calls but once in a blue moon. No one can call me and lots of times I have no dial tone or I can call but I cannot hear them and they cannot hear me. I have begged for help from AT&T and they do absolutely nothing! I watched my data flying off my phone and I don’t stream! AT&T made me pay for data I did not use many times upwards of $500 and yet my service is disgusting and all I get from them is you must not get good reception! You would think after all the money I have paid them they would at least send me a signal booster for free!!!! If they don’t help me soon I am changing carriers! And this iPhone X is nothing special and doesn’t pick up any better than my iPhone 6S! I was lied to and although I am giving AT&T the opportunity to make things right I grow sicker of them daily! AT&T fix all of the problems and heartache you have caused me!!!