...ask the mod to delete their thread.
Mods will not delete threads, they will only delete old bumps, and I see that many times. What is strange is that after deleting old posts, there is generally no change in behavior. It is possible that some users have no idea about these rules at all.
If any of users who have earned merit in that last year post in the ANN thread, the bump score of the thread will increase and this is exactly what they want.
Good warning, although bumping doesn't just happen in boards where is allowed to bump thread, but also in some other boards where this option is not available. I remember alerting a few users about this, but there was no reaction - like talking to a wall...