I'm sorry

I am really frustrated with a certain child in my family who accidentally hurts people but doesn't feel it necessary to say I'm sorry. I've had several talks with said child about even if it was an accident you still hurt someone and you should say your sorry. But this kid will some times argue that they didn't in fact hurt one of their siblings while that siblings is crying from being hurt. It is so frustrating. Well last night this child hit me in the face with their jacket zipper, right on my lip, a very sensitive area. They could see I was hurt by my face but instead of saying anything they just acted like nothing happened. I even said, "That really hurt. You got me right on the lip with the zipper from your coat." Nothing. It made me SO mad. Then fast forward to tonight. I was walking down the stairs and I rounded the corner and accidentally stepped on their un-shoed foot. I was wearing my hard soled slippers. They grabbed their foot and started hopping and saying "ouch" immediately without thinking I said, "I'm so sorry. I didn't mean to. Are you ok?" Then I stopped and looked at them and said "mm maybe I'm not sorry because you know after all it was an accident and I didn't mean to hurt you so maybe I'm not sorry." They knew I was trying to make my point from last night's incident. Then seriously not even two minutes later one of their siblings did something to hurt them. And that sibling IMMEDIATELY said, "I'm sorry". To which I said, "Look did you see two times you got hurt accidentally and both of us right away said what???" I was able to use that to show them how if neither one of us would of said anything to them they would of felt unloved and uncared for by us. And when they don't apologize when they accidentally hurt someone they are telling that person they don't love or care for them. It should be the first thing out of your mouth if you hurt someone whether on purpose or by accident. This is a major struggle for this child. Not sure if it is a pride thing or what. But other than that they are so fun to be around, helpful around the house mostly without complaining, obedient, loving, and just a great person. I just really wish we could get this "I'm sorry" learned and they will go far in life.