Curro St Dominic's - apathy or negligence?

My son is 2½ years and in Curro St Dominic's in Newcastle KZN since end of last year. Last Thursday he was picked up from school with 50 odd insect bites on his tummy down to his groin. He was complaining it was sore. His nappy pants had been changed about half an hour prior to my wife picking him up. She noticed the bites as soon as they were home. My wife tried to contact the teacher to ask what had transpired and why she wasn't informed earlier or when she went to the school. She received no reply from the class teacher. The week before my son also had a few insect bites. This had been told to the preschool head by myself. She gave me the impression that this was an isolated incident. However when my wife checked there are at least 6 (probably more) children in the school with the exact same insect bites. But this was never communicated to us or other parents. I spoke to the preschool head yesterday and explained that it's unacceptable that my child gets extensively bitten at school and they are either not aware of this or worse they ignored it. Its extensive bite marks. The only way it could have been missed is if they were negligent or ignoring my son. Either is unacceptable.The head of the preschool said she will speak to the class teacher about this and to communicate better. As to the bites I asked why the school hadn't informed the parents of a potential health risk. Makes me question whether they wanted to keep this quiet and pretend the bites happened at home. Yesterday my son was distraught at school which is unusual. Didn't stop crying even after he was home. The class teacher turned her back to my wife and didn't explain why he was upset. Which leads to the question of what did the class teacher do/say to my son after she got reprimanded by her senior. This is not the first altercation we've had with the preschool. We've had the same issues about communication and why my son is pushed into a corner during the day. But nothing has changed. The principal seems to have a closed door policy. He refused to meet with us to discuss the above issues earlier this year. Why is this? Curro St Dom's have our children in their care. You cannot shirk your responsibilities to nurture, teach and keep them safe. My son also has rights! And we want answers when it comes to what's happening to him in that school.