Blocked by MX, contact for MSN.COM postmaster ?

Does anyone have a contact at that will respond to a situation
similar to this thread? Our email queries to support/abuse/etc have gone unanswered.

We have a class C allocated from one of our /16's that has been
blocked by MSN without any prior warning/notice from them.
Unfortunately for our customers, this class C is heavily subneted and
their efforts to block a potential spammer is akin to throwing the
baby out with the bath water. a /32 I can understand, but a /24? Why
not a /23 or heck a /8 - carpet bomb everything...

We have *always* been responsive to spam complaints so to be blocked
without any contact/notice is a bit disconcerting. I'm as anti-spam
as they come, but this is a bit extreme...