@Ash59,
This happens to other people too (search in community) and i can understand it is very annoying when Airbnb is not providing the reason. But the "terms of service" state they can deactivate an account whenever they want and withou explanation. So you need to be persistent and ask again, especially when they promised you an email from Security. In the mean time you can try to think of some reason, it could be for example:
- reported to Airbnb by a guest or host
- complaints from neighbours
- safety issues
- violation of local law
- fraude
etc..
Best regards,
Emiel