Hi Sparky,
Start here:
AdWords Trademark Complaint Procedure
You'll need to follow through with filing Google's Trademark Complaint Form. In the form you will specify you are the trademark owner and detail what account # (client ID) and the domain(s) you authorize to use your trademark. Once your submission has been approved by Google, you should receive a reference # and all unauthorized advertising done on your trademark in ads will cease.
Good luck,
Danielle