From Everything.Sucks

AT&T Mobility LLC or AT&T U.S. Mobility, also known as AT&T Wireless, marketed as simply AT&T, is an American telecommunications company. It is a wholly owned subsidiary of AT&T Inc. and provides wireless services in the United States, including Puerto Rico and the U.S. Virgin Islands. AT&T Mobility is the third-largest wireless carrier in the United States, with 93 million subscribers as of the end of Q2 2020. Originally known as Cingular Wireless (a joint venture between SBC Communications and BellSouth) from 2000 to 2007, the company acquired the old AT&T Wireless in 2004; SBC later acquired the original AT&T and adopted its name. Cingular became wholly owned by AT&T in December 2006 as a result of AT&T's acquisition of BellSouth. In January 2007, Cingular confirmed it would rebrand itself under the AT&T name. Although the legal corporate name change occurred immediately, for both regulatory and brand-awareness reasons both brands were used in the company's signage and advertising during a transition period. The transition concluded in late June, just prior to the rollout of the Apple iPhone.

An outraged customer shared in a review "Cingular's customer service is atrocious. They do not care about their customers. They completely misled me with their coverage capabilities after they merged with AT&T. They should be held accountable for what they promise and should not be allowed to intimidate customers, with fees, who are simply trying to find a resolution. They are a horrible company and I am filing a complaint with the PUC, so hopefully their business processes will be forced to be changed."