I would DEFINATLY find another day care. Please follow you gut instinct!!.
I had somthing happen to my DS who was 3 ( so much older). I went to the day care ( where he had never had a problem before, he had been going for about 6 months) to pick him up one day and one of the girls told me he had been WINGING!! all day. I thought that was a strange thing to say but carried on, when i got to him he was sobbing and obviously verry upset. I had never seen him like that before at DC. The director then told me that he'd had and accident and wet his pants.( he was potty training). So in the car on the way home he was still crying and he told me that one of the teachers smacked him!! i was fuming. went back down there without the boys and talked to the girls. no one owned up and I never have taken him back. To this day its been 6 months since he last went, you cannot talk to him about going to daycare or kindy or anything. he just breaks down and cries!. Its so sad.
Sorry for ranting, I just want you to know that its not acceptable and I am so glad that I followed my instinct and never took him back, somthing obviously happened to him there.