keep on at

keep (going) on at someone or something

to continue to complain about or scold someone or a group. Don't keep going on at him. Give him the dickens and be done with it. Please don't keep on at the committee. They did the best they could.
See also: keep, on

be/go/keep ˈon at somebody (to do something)

(informal, disapproving) keep criticizing somebody or telling them what to do, etc: He keeps on at her all the time about her smoking.
See also: keep, on, somebody