AT&T "hides" the fee in an easy-to-miss spot in customer bills, the complaint says, and it "misleadingly suggests that the Administrative Fee is akin to a tax or another standard government pass-through fee, when in fact it is simply a way for AT&T to advertise and promise lower rates than it actually charges."
https://arstechnica.com/tech-policy/2019/06/att-sued-over-hidden-fee-that-raises-mobile-prices-above-advertised-rate/