What a horrific situation you have found yourself in @Laura4076 , it can and does also happen to others who rent properties through other avenues, not just ABB.
We tend to only hear about the one's through ABB unless there's a court case involving the Tenancy Tribunal here in New Zealand and some of those cases are abhorrent.
What is it with people these days to be so brutal and disrespectful of others property and think they can rip people off, including fellow tax and ratepayers?
I hope your camera is set to pick up on where your letterbox is to see if it's them collecting the mail.
You could always reach out to those in the neighbourhood and see what camera footage they have as they to need to be made aware there's criminals in the area, and may be able to assist in getting a successful prosecution.
Have a browse through other listings, including Private Rooms and see if you can get someone to Co-Host and check on the property when you are unable to get there during the week.
I hope they have not checked into another nearby ABB.
You may like to ensure @Catherine-Powell follows up on that to from the back room.
Bless the Superwoman she is at the moment to deal with all these cases.
Meanwhile take it easy on yourself @Laura4076 and good on you for your bravery in dealing with these thugs.
Keep safe