Short answer: No, do not pay the SORBS fine to get delisted.
What is your IP address / Who is your ISP? Are you a residential or business customer?
If you are not getting help it sounds like you are a home user and that you are trying to send email from your home (residential) IP address which is listed on the SORBS? Are you trying to run your own mail server? You can probably fix the problem by configuring your mail server to relay outgoing email through your ISP's smtp relays.
If you are a business customer this really should not be a problem. Make sure your ISP updates the reverse DNS for your IP address and all of the IP addresses in at least the same /24. The naming scheme should look static in nature with names like static-1-2-3-4.market.your-isp.net. Even better would be a naming scheme like that for the /24 and a custom reverse DNS entry for your specific IP address such as mail.your-domain.com or smtp.your-domain.com. Once this is done have your ISP request that the entire /24 (your IP address and all of the IP addresses around it) be delisted and removed from the SORBS database. Warning! Only one person should submit the delisting requests. If both you and your ISP try they'll delay or refuse to delist you. Let you ISP handle the delisting process.
If they do not understand feel free to forward them the link to this information.