to stick to your guns = to continue to have your beliefs or continue with a plan of action, even if other people disagree with you

Despite the advice from his surrounding, he stuck to his guns on this issue.

To Stick To Your Guns

 

to stand one’s ground = to maintain one’s position

The captains of these ships stood their ground and fought, disobeying their admirals.

To Stand Ones Ground

 

to dig one’s heels in = to refuse to change your plans or ideas, especially when someone is trying to persuade you to do so

She had tried to convince her sister to rent a hall, but DeDe dug in her heels and announced that she’d always dreamed of getting married in Mama’s backyard.

To Dig Ones Heels In

 

to put one’s foot down = to use your authority to stop something happening

Enough is enough. It’s time to put your foot down.

To Put Ones Foot Down

 

to not give an inch = to not change your opinion or decision

However I tried to convince her, she didn’t give an inch.

To Not Give An Inch %d0%ba%d0%be%d0%bf%d0%b8%d1%8f