@ OP - just disavow all of your inbound spam links, clean the outbound spam links from your own site. Tell google about it and wait.
Don't pay anyone for this.. you can do it yourself in like 30 mins.
https://support.google.com/webmaster.../2648487?hl=en
If you need your whole backlink profile in an excel sheet, PM me your URL and email address and I'll gladly send it to you.
p.s doing this should remove any penalty reasonably quickly, but of course if your site was getting its rankings from spam which you "are discarding" via disavow, you will of course need to replace those links with quality links in order to regain / exceed your former rankings