Copied from my email response to your Contact Us:
"The 30% discount only applies when your renew while your subscription is still active. Your subscription expired in early December.
If you were to resubscribe now, there's a 3 month difference between your expiration and renewal, which is more than the 30% discount is worth. So, by waiting, you've saved a similar amount as if you were to have kept your subscription active the whole time.
The discount is offered because users that stay continuously up to date with each release require less support, and we pass that along. I hope if you choose to renew again that you'll keep your subscription active before it expires next time, in which case the 30% discount will automatically be applied."