Pinnacle is a great book, but realize its limitations. Its the Wal-Mart of sportsbooks.
You can't expect the same level of service at Wal-Mart that you would get at a high-end store with higher prices.
That being said, Pinnacle has answered the few questions I have had satisfactorily and within a reasonable amount of time in the 3 years I've been with them. Only by e-mail, though, and I understand why.