I've had online chat agents perform numerous tasks without issue, so I would not say they are all "useless". Do you mean you were rebooked LAX-SLC-CVG? (Being rebooked from LAX-ATL-CVG to LAX-SLC-ATL makes no sense). Assuming your asked to be rebooked back to LAX-ATL-CVG and the connection at ATL was under 4 hours and thus legal?