Termination of Services

I have tried to terminate my ADSL line. I have tried to email but this rejects- ********** SMTP error from remote mail server after initial connection: host smtp.telkom.co.za [165.143.155.37]: 554-smtp.telkom.co.za 554 Your access to this mail system has been rejected due to the sending MTA's poor reputation. If you believe that this failure is in error, please contact the intended recipient via alternate means.

I have tried to call and after holding for 20mins was cut off. Tried the website chat but this is off line. Very annoying!!!