I'm thinking of refusing to pay my friend for the cost of fixing a wall I broke.
Why don't you want to pay for the wall that you broke?
Because she did something that hurt me.
I understand you are upset that she has hurt you, but you should always pay for what you have damaged.
That is my best friend! I'm not going to hurt her.
Well, you'll hurt her in a way if you don't pay for the cost of fixing what you damaged. You should pay what you owe, and then have a separate conversation with her about how she hurt you.