graciem Sorry to hear about your problem
I had something very, very similar when I was planning DS's birth. Couldn't contact the midwife, couldn't get confirmation homebirth was booked, didn't really get to discuss it with anyone before hand.
This wasn't helped by my friend who lives in a different part of London and due at the same time as me getting loads of support and "extras". She had a home birth support group, midwives came to see her at home and her birth was planned from the beginning.
Well, I had my homebirth. It turns out that where I live they are just a bit rubbish at the anti-natal care in terms of answering the phone and returning calls. They also don't do any of the "extras" that my friend got.
Having said that, my home birth was wonderful. The midwives were brilliant and, like you, I wondered if I would even be able to get to speak to one, nevermind get one to come out!
When the time came it was the delivery suite we rang and then we got the mobile number(!!) of our lovely, lovely midwife who about 8 hours later delivered DS.
So, my advice would be... keep planning your home birth. Mention it at all of your check-ups so it's on your notes. Do your home work so you know what to expect (as much as you can).
Good luck!