When you're trying to check in and they don't respond or give you the proper information just message the host and threaten to cancel your reservation. Thats the only way I got a response after 2 hours of phone calls, messages, and sitting in a lobby wasting my vacation time. They will not answer the phone.
Airbnb support can't do anything to get the check in information sent over, so I wouldn't bother calling them. There are plenty of hotels in the area so don't be afraid to huff it somewhere else instead of wasting your vacation time!