Need help to handle AdWords problem

Hello everyone, im new here. I want to share my problem and hope I can find the solution by asking people in BHW forumCouples months ago, I start using some adwords services for my website from 3-party google ceritified partner company. To be blunt, the service was kinda disappointing and i am trying to cut off the google adwords service from that company. When I say this to them, they saying 'if we cut off the services, they will attack my site with Black Hat SEO and some other attack methods. The question here: Does anyone know how report this company to google? How to prevent the company from attacking my site?Please help me here....

attack !!!!!!!!
interesting ....
pleas pm that company url ...

and pls post their email .. where they said .. they attack

well, they said bluntly face to face to my company's people. so i don't any proof until now, that's why im still waiting for them to attack and try to prevent them. do you have any yahoo account. I am interesting to talk with you ^^

First of all I think they are just pushing the fear factor. Second you can report their site to Google via Webmaster Central. Use Google to find the proper link.