You should respect the law and change the name or take the site offline until you receive appropriate permissions.
Please note that even licenses as GPL or MPL (that govern the Firefox code for example) give you permission to use the code, not the trademarks of the project. Ubuntu had to make a Linux package called "abrowser" ( https://launchpad.net/ubuntu/lucid/+package/abrowser ) simply because Mozilla didn't agree with branding their modifications as "Firefox".