I don't give a shit
This phrase is like throwing your trash on the ground and walking away. You don't care what anyone says or does. You're just done with their nonsense.
My boss said I had to work late. I said, 'I don't give a shit.'
My friend talked my ear off. I replied, 'I don't give a shit.'
I got a call from my mom about my uncle's cat. I said, 'I don't give a shit.'