harp on the same string

go round in circles

To repeatedly do the same thing without making any progress.

bad penny

A person or thing which is unpleasant, disreputable, or otherwise unwa …

one and the same

The selfsame person or thing. Used to emphasize the identity or equiva …

harp on one string

To dwell on a single subject with disagreeable or wearisome persistenc …

keep on about

To harp on; to continue to speak or discuss something repeatedly.