I know it is not live or real time chat, but sending a private message to the att customer care team can help. Sounds easyer than looking for a link you can't find for whatever reason.
Pick one of there care team links (any will work) and send a message with your name, account, phone, contact email, best time to connect with you, and a message with your needs. Give them a couple days or so to get back with you, and I hope they can help.
U-verse problems, ATTU-verseCare.
Cellular Problems, ATTMobilityCare.
Billing/other problems ATTCustomerCare
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Good luck