Spam from inside qwest.net

Im being spammed from a netblock inside qwest... ive made three individual attempts to mail their abuse people and get nothing but their automated bounce message... Has anyone successfully dealt with spam or abuse inside qwest.net ? At this point im considering blocking the MTA concerned from connecting to my server, but then theyll just go to my backup MX (who doesnt want to impose the same restrictions that I am willing to.. *frustrated*. Mark. - To unsubscribe from nznog, send email to majordomo(a)list.waikato.ac.nz where the body of your message reads: unsubscribe nznog