> Att was destroyed as soon as they sold to cingular.

The story of AT&T and Cingular is much weirder, see [0].

Once there was AT&T Wireless that became Cingular (with the help of SBC). Then SBC bought AT&T (landline) then the combined AT&T bought Cingular that became AT&T Wireless again.

[0] https://www.att.com/Common/merger/files/pdf/Cingular_timelin...

EDIT: typos