Call 1-888-865-3193 and referenced code: HBO0703
If asked, it came off a mailer. It is auto-terminating meaning it will not auto-renew without you knowing about it. Took me about 1 minute and they say it takes up to 72 hours for it to be added to your service.
If it works for you please post letting me know! Got this off Slickdeals and they want to know if it works.
Here is what the mailer looks like:
