Keep going. 

I'd keep contacting the Code Enforcement Office (based on the squeaky wheel gets the grease theory).

Other things to keep in mind: they appeal to a different market segment.

They are worried about underwriting the deal to today's costs with the concern that rents might not rise to cover the additional costs (keep in mind, I'm in FL with huge insurance rate jumps...but other areas are feeling similar pain).

Keep in mind any good plaintiff's attorney is going to bring all parties incidentally related to the legal claim in as an additional defendant.

Just keep a close eye on them.

I think getting in a habit of keeping deposits sets you up for stress in the future. 

You have a system that's working for you, just keep repeating.

I currently have 5 mortgages but have not been great at keeping track of the details such as costs associated with each individual property.

@Kiefer CheneyTo do well in real estate, learn well, set clear aims, gather a team, check out deals, pick a main area, go for it, keep on track, and learn from slip-ups.