dig your heels in

dig (one's) heels in

To cling stubbornly to one's beliefs or wishes. Please let me tell my side of the story before you dig your heels in on this, OK? Well, I told Grace she can't go, and now she's dug her heels in as if this party is the most important thing in her life.
See also: dig, heel

ˌdig your ˈheels in

(informal) refuse to do something or to change your views: A number of councils have dug their heels in over the government’s request to reduce spending. OPPOSITE: give way (to somebody/something)
See also: dig, heel