Biting at daycare

My child (1.5) keeps getting bit at daycare by the same child (7 times in 5 weeks). This child also bites other children. The directors have put a plan in place but it doesn't seem to be working (one teacher dedicated to watching the biter to prevent future incidents). I'm at the point where I want to ask the director to unenroll this child. It doesn't seem fair for us to leave since my child isn't doing anything wrong but I won't continue to put my child in this situation. Any advice?