Destroying 20 blocks on a house could also considered "messing up a house". Tbh, that claim bothers me a little. Also, if this was that garage door peng has that was a pretty complicated redstone build and that should be considered a moderate to a severe grief.
Since you decided to intentionally break a second rule after being given a second chance, I'm still voting for a perm ban.
Since you decided to intentionally break a second rule after being given a second chance, I'm still voting for a perm ban.