回複：回複：回複：回複：這錢可以拒付嗎？

I had my car repaired several times in this shop.
The paper work is done after the repair.
Last time I had two parts of the car repaired, I signed one bill. But I refused to sign the other one, because I found they cheated me on this repair. So they have no my signature for the second repair.
　（Every repair has independent bill）