Vodacom and Spamhaus.org

Today is day 4 without being able to send out any emails. I can receive but can't send out any. My internet service provider checked everything from their side twice, and the outcome was the same. I need to ask Vodacom, my fibre service provider to contact zen.spamhaus.org to lift a block on my ip address. Who do I contact, because they simply don't know what I'm talking about. Is there anyone that can assist please.