L.L.
Kids bite and it sucks! But....If after repeated meetings with your day care center, this is still going on, it would lead me to believe that they are not watching the children very well since they keep allowing it to happen. I personally would leave that center and find a new one. Or ...use the him or us approach. Either the biter leaves or your kids leave. Since you have two kids there, they'd be more likely to take your side I would guess.
If I was the daycare that had this problem I'd keep my eye on that kid like a hawk...and after counseling the parents several times, I'd ask the biter's parents to find a new day care.
Good luck!