comcast abuse/admin?

If anyone from comcast is here, we would like to talk to someone on
your end about abuse from your network (mainly inbound spam from
a lot of your netblocks to our mail pool.)

Basically we would just like to blot out a number of netblocks in
your space from our mailservers that just feed us a constant spew of
spam, but we welcome dialog from your side to ensure legit email is
unimpeded (by telling us where your outbound mailhubs are, etc)