I don't remember seeing or hearing about any such incident, but I don't handle donations. Also keep in mind that, compared to other games, most of our bans are very short-term (1 day - 1 week). Only very few people have managed to be banned for extended periods of time and permanent bans (that are enforced) are nearly non-existent.[Spoiler]
On the other hand, you have Firepluk
who is one of the top donators, yet also tops the list of most bans.