The ads actual URL goes to a completely different site. There is no contact information on the site and the domain registration uses third party "privacy" protection. Major corporations typically don't try to hide their true identities.
I'm sure that lots of advertisers have tried to get away with a lot of things on AdCenter and the Google and Yahoo conterparts. The point is that I informed Adcenter about an ad with serious violations of their own editorial guidlines and they refuse to remove the ad.
I think you got waylaid on the trademark issue. I definitely would consider this more of a violation of editorial guidelines and should be reported as such. If you've reported it, that's pretty much all your can do.