Medicross Newton Park hits a nerve for just filling a tooth

My wife went to a dentist last year for a filling at medicross newton park the dentist hit a nerve and all he said was he was sorry. My wife is in so much pain when I phoned them today they said there is nothing they can do. I mean how is that okay for a dentist, it is not her fault that he hit a nerve now she is in so much pain, I will be taking this up with the medical board.