cancelling automatic renewal

After a bad experience with an automatic renewal, I wish to cancel the automatic renewal on my three-pack anti-virus package.  But the button on my account to do that has disappeared despite two differenct help instructions on where it should be located.  I also cannot seem to get through to Norton unless I provide original product keys and other information I don't have (not all my computers are at this location).  Can anyone help me with this?  I would be very grateful.  Thanks