It sounds like their customer support failed you. Whatever tool they were using to track your email thread failed or someone acted too hastily and responded to the thread inappropriately by asking for the same information. You are right they made a mistake in sending you two emails and it is annoying they are holding your money.

I have no inside information about Airbnb, but I'd guess they are slowing moving the money to try and prevent fraud on their system. Basically, A stolen card being used for a high value amount. Obviously that is annoying to anyone who is waiting for money, but I've seen it happen in many situations where money is transfered.

Are you a frequent hoster? If you have a lot of money coming in for your apartment, it is much more likely that it would be transfered quickly.

If you are a frequent hoster, is this a unusually large amount at once? Or is it from someone who is using Airbnb for the first time?

In the end, it sounds like your experience wasn't so great. But I'd hope you remember that it is just people on the other end answering your email and trying to prevent fraud. Many of those people answer hundreds of emails a day and probably make mistakes as often as anyone else. I hope everything works out for you.