Finally I find the guts to cancel my son's day care, thanks to the ladies at www.ivillage.com message board for 2-3 years old.
He was going to a day care on and off once a day weekly since he was 6 months old. All his day cares were small home based but licensed. The first one he went to since he was 6 months old, it was OK until he was a year old then for two sessions he would cry uncontrollable that the teacher called me to pick him up and after the second time she told me that it's better to stop the day care.
The second one was the day care of a family friend, he was familiar with them and very comfortable around them. I have to day he is a bit shy around new people.