These free phpbb boards want you to pay $20+ if you want
a copy of your SQL database. Some of these board hosting
companies are fly-by-night operations and have little or no
support. So even if you are ready to pay them to get your
database, there isn't anybody reliable at the other end, ready
to take your money and give you a copy.
If you are not lucky in getting a(any) response, I would do this:
Trace your board's domain IP address. Do a "Whois" search
and find out who the real owner of the board hosting company
is. With that info you'll have their real email address & location.
They'll be inclined to take the mail more seriously on that add.
Other than that, the only (rumoured) way I have heard it done,
is to write a program called "crawler" that will go on the net and
crawl all over your board, automatically generating a MySQL
database for your board. I have heard people in-the-know who
can do this. Unfortunately, I am not one of them.
Good luck, amigo.
Sheikh 'Scrawler' Chilli