how to turn on call forwarding via website; ATT traditional landline outage; it's an ATT problem, not house wiring; repairs pending

Have traditional ATT landline since last century, in present home since 2005.  Now there's a new landline outage x 48 hours;  apparently started during recent heavy rainfall.  Not a home wiring problem, is on ATT end.  Have submitted "repair ticket" request for service via website (att.com/repair), and received email confirmation that repair ticket is in process.  I want to turn on call forwarding for the landline so to forward any calls to my cell, but I can't do so using the actual landline phone itself because THE LANDLINE IS NONFUNCTIONAL.  It seems reasonable that one could turn on call forwarding via the ATT website, but I can't find out how.  Have tried calling ATT (800.288.2020), and was misdirected to an ATT wireless agent;  she transferred me to "landline services", but I've been on hold for 1hr28minutes and counting, so no joy there.  Anybody got any ideas?  Thanks.