File a complaint with the BBB (Better Business Bureau).
On their website, it has a list of criteria for a complaint, including:
"The complaint alleges a problem experienced with the services or products that the company provided or agreed to provide"
Here's the link:
www.bbb.org
The top of the page should have 3 boxes, the middle one is 'File a Complaint'.
It's pretty easy... and based on what you've said... they will be able to put pressure on the company to honor their ad.
Good Luck!
