My Bill is Incorrect and I'm Tired of AT&T

My bill is incorrect. I never wanted unlimited. I was told last time I asked to lower my bill that the only thing that could be done is an upgrade to unlimited at no extra cost. I have the transcripts to prove it. I am only 1 person, age 25, and I'm having to work from home now. Before I was only using about 80 GB of 1024 GB. I said I wanted the smallest and cheapest plan available. I don't understand how my bill could have changed this month and as soon as I can figure out how to get a different internet service provider in my area I will. I'm also being told I can't be connected to a specialist on the chat.