time and (time) again
Repeatedly; on multiple occasions. Why do you continue to trust John when he has lied to you time and again? Time and time again, they have violated the rules, yet you have taken no action against them.
time and again
Again and again; repeatedly.
time and time again
Repeatedly, often. This version of the earlier time and again, or again and again, dates from the late nineteenth century. Evelyn Waugh used it in The Ordeal of Gilbert Pinfold (1957): “. . . envying painters who are allowed to return to the same theme time and time again.”