@John0 (can't seem to tag you). I have had the opposite experience, i.e. I have had really great customer support from Airbnb, including having a retalitory review removed and, another time, them contacting problem guests and telling them to follow my rules or leave without a refund.
I even started a thread about it, because I got the feeling that people only post when something goes wrong, not when it goes right. I think this is true because a lot of the responses to my thread were from hosts who said they also received excellent customer service.
However, it's really worrying that the level of service is so inconsistent. One rep tells a host something is simply not possible and there is nothing they can do to help, while another is 100% helpful to a host with the same problem and it is sorted out quickly.
If something is against what Airbnb claims to be their own policy and their own rules, then they have no right to backtrack on that, for example, the claim that the Host Guarantee has us our backs, or that guests have to follow our rules or be held accountable. They need to deliver what they promise and deliver it consistently.
If I had any advice to other hosts experiencing problems with getting support, I would say don't email in the first instance. From what I can tell, this doesn't get very positive results. Always call and speak to a rep in person (and do it calmly). This might work, it might not, but I think there is a better chance than if you just email.