first disavow ~70% of your links in one go
make some sob story about your SEO guy giving into peer pressure and buying stuff from chinese/indian sellers.
tell them you have fired him since the incident but unfortunately you don't have any reports of what links he bought and that you would like to regain your place in google and that you will redeem yourself by offering your audience only the best in terms of quality content & blablabla...
after ~ 1-2 weeks they'll message you back saying that your site still isn't google search compliant and give you a type of link (usually they just send 1 link but if you're lucky they'll show you more)
disavow the rest of your links ... and I mean all of them!
edit your htaccess to 404 or 301 all your links to google or whatever site you want.
send them a message back explaining that you are really eager to get back on their good side and also tell them you htaccessed all your links to 404... they can't see your htaccess but they might manually check if your some links still point to your site.
after about 2 more weeks you're off the hook.
after that never build links to your main domain. point them at 'www' because that's a subdomain of your main. have 'www' 301'ed onto your main domain.
at the next penalty just remove 'www' and tell them you have deleted the 'page' with outstanding issues towards their quality guidelines.
create 'www1' and redo the whole process...
this .gif should be dancing... it will when you click it.