Block user from community but not support tickets

We have a customer that we would like to block from posting in our community forums, but we still need her to be able to enter support tickets as needed. She is paying her support contract with us so she needs access to tickets. But she is abusing the community forums and we want to block her. I see that I can turn on moderation, but then that is turned on for everyone. I would prefer to find a way to fix this issue while not interfering with the way anyone else uses our forums. Any suggestions would be greatly appreciated.