Lady Victoria wanted to make sure that this guy learned his lesson and that he never messed up again. That is why she chose to use her high heels to dominate him. She made it very painful for him and it was through that that she was able to tame him. He was in a lot of pain in the process but he never forgot what she did to him.
Lady Victoria and her friend were not ok with the things this slave did and they had to tame him. Lady Victoria enlisted the help of her friend and the two of them ganged up on him and they used their high heels to trample his balls. He felt excruciating pain before the two of them were done with him and the allowed him to go as they believed the point was home.