Newbury Comics customer service phone number: 617-779-5973.
I've placed several recent orders with them, both through Amazon and directly through their site. Generally, the orders have shipped the same day or the next business day. For orders directly through their site, Newbury ships by first class or priority (for 13 ounces or over) mail, and not media mail. I can't remember whether they use first class for Amazon orders, but I believe they do. Most of the orders have taken a few days to arrive in Philly, but some have taken a bit longer (due to the Postal Service, and not Newbury).