Hai! =3
For clarification, there is the “No stealing” rule though it is categorized as a grief in:
In which by stealing, you are clearly “Modifying” a structure in your case, the “shulker boxes”.
Added for more info from the term Griefer from Wikipedia:
Causing a player disproportionate loss or reversing their progress.
- Destroying or modifying other players’ creations without any permission
As for being unbanned for the rule not listed in the website, there is:
Though as I explained, it is there, & so we would not change how we operate the server for the reason being that people could not follow the rules.
However, since you did steal reasonable obtainable but was in large quantity of items, I am willing to reconsider in a month.