Good question! It can be very frustrating for debtors (and LITs!). I’ve had some success in referring the matter to the OSB’s creditor compliance program. It sounds like you’re hitting the right bases.
The only thing that I could offer is that I’ve also sought an injunction from the courts as to collection, but it did take a lot of time/effort to do so. If I recall correctly, we were able to get some small amount of costs given that they were flagrantly ignoring the BIA and multiple notices/letters that they were sent.