Yes, listen to Lao Mao.

Calm down and focus on your daughter for now. Figure out what you can do to make your daughter more comfortable and less likely to have long term affect. (Talking to doctor, searching the Internet.) Keep all the records as detail as possible, including the time you need to take off.

At the same time, I would search for another daycare as this one seems unprofessional.

After all these done, you can talk to school again. If still no result, talk to regulatory state department and file a complaint against it.

After all those, depends on how much you want they pay, you can sue them either at small claim court or find a lawyer.