Almost 4 Year having tantrums at Daycare

My almost 4 year son has been having tantrums at Daycare several times a week.  He is a very sensitive, intelligent and strong-willed child.  We are pretty strict at home, we put him in time out as soon as he begins to be defiant.  But for some reason at daycare he throughs these wild tantrums that include screaming at the top of his lungs, kicking and screaming.  When these tantrums first began, I punished him as soon as he got home; we'd talk about what happened, then I'd sit him in the corner for 4 minutes followed by me taking a toy(s) away; but still the tantrums at school.  I'm beginning to feel very frusterated with the staff.  I am paying them to care for my child and yet they are unable to resolve his tantrums or prevent them from occurring.  I don't know what to do at this point.  I could look into other day cares, but I'm afraid I'll have the same situation.  I'm not sure how to get my 4 year to respond to others the way he'll respond to me.  PLEASE HELP!!