Port 6*47 is the Gnutella port. You aren't being attacked, you are running a Gnutella client. Gnutella is sending out packets to other servents, but their attempt to reply is being blocked by ZA. Open port 6*47, or tell ZA that Gnutella is OK (not sure how you do this, unfamiliar with ZA).

If you complain to your ISP, you will make yourself look foolish.

Regards,
Jack.