Picked up my kid with two huge bite marks on her arm and don't know what to do with the school now.

My kid is only 2. Today i picked her up from her class and her teacher comes over to me in tears. She also had a piece of paper with her. I'm confused at this point, as I have my child on me, happy to see me and telling all the other kids "bye!" as she normally does. The teacher, between sobs, tells me that my kid was bitten TWICE on the right and left arm. When i checked her little arms, the bites where so close to have been bleeding, I have no Idea how it did not broke skin. The incident happen early in the morning and I picked her up in the afternoon and she still had huge red marks. The teacher then apologized over and over because both teachers didn't see anything. They found the marks after the fact. This is where things don't add up for me. My kid is tough, is true, but I don't think she would have not cried or screamed when someone is holding her arm and sink their sharks teeth in her. Also, why wasn't I called? My sister gets a call just from a bump on a knee while my nephew was running and had a lil pink spot (different school, different state). Yet, my child had purple/strong red marks on both of her arms, and not a single call.The front office didn't stop me going in or out to talk to me about it. I had to go in myself and they just said "it happens, this age kids are like this, and we cant say it wont happen again." Um...it happen twice in one day with my daughter and then he went and bite another girl (I know is a he because the office let it slip.)The front office wont do anything about it as it is, besides the incident report.No callWont do anything to have the child that clearly has a problem be watched by another teacher for a while (it is 7 to 1 teacher ratio).Didn't stop me to tell me what happen.All of this are now red flags to me. I don't know if i should be looking for a different school. Last week, my kid came back with HFMD because they lost a teacher and I don't think the cleaning procedures where followed. This week is huge bite marks on her arm, that even though it has been 6 hrs after i picker her up, she still has marks.What should i do? Should i confront the office? should i look for a different school? If they could not watch her and she gotten bitten twice by the same kid....what else can happen? What if the kid hits her on the head hard? what if she falls hard and no one sees it? I'm now thinking the worst possible scenarios and I can't say I trust them with her care. One mild bite, I understand. What she has on her arms, and twice? believe that she didn't cry? and not calling me? Is to hard to swallow. This whole thing caught me by surprise and this is my first and only kid. So I don't want to over react but I feel im not under reacting. Whats the right amount of reaction in this situation?TL;DR:Boy bit daughter on both her arms that nearly broken skin. still have marks after picking her up 6 hrs ago. Front office tossed it to "Boy's will be boys" type of excuse. Feeling like im under reacting and need advice. via /r/Parenting https://www.reddit.com/r/Parenting/comments/4pqj6b/picked_up_my_kid_with_two_huge_bite_marks_on_her/?utm_source=ifttt