how to get delisted from spamhaus DBL

Dear Experts

my domain is listed in spamhaus DBL , we have taken all measures for not sending promotional emails to the non-opted contacts and made  several requests to the spamhaus to remove  our domain from the list but they are not supporting in this, they keep replying like the below posted, PLease suggest us the way on getting delisted, it is affecting us very badly please support

Hello,

We have reviewed the DBL listing for domain.com and decided that
we will retain that listing at this time. We do not discuss criteria
for inclusion in DBL, however it includes many factors. Your domain
matches several of those criteria.

DBL listings expire over time, so if our systems do not see your
domain for a while it will drop out of DBL zone. Many factors which
affect your domain's reputation may also change over time, so by
engaging in good reputation practices it will eventually drop out of
DBL. For more information, please see DBL FAQ "Why is my domain listed
in DBL?" http://www.spamhaus.org/faq/section/Spamhaus%20DBL#371