Federal Limosine Failure to Honor groupon Dallas, Texas

STAY AWAY FROM THESE GUYS!!!! What a ripoff! I purchased a deal they offered through Groupon. Knowing I would be in dire need of a ride on this trip I held onto it until it was time to use it. I contacted the them (Federal Limo) via the phone to book it a week ahead of time and some guy answers like it's his personal phone & tells me to go on to the website 24 hours before I needed the ride and list my Groupon number in the booking, which I did this morning. I followed the instructions EXACTLY as told. First I get a confirmation of my request. Then at 6:11 PM, I get a cancellation (email, not a phone call!!!) of my booking tonight Federal Limo sends an email saying that they have no record number of the Groupon I purchase and "oh by the way, we're fully booked." Not only am I screwed for the amount of the Groupon I purchased, but now I'm also screwed for a ride. DO NOT RELY on these people to pick you up.  Now the owner is calling me and telling me to rescind my bad review on YellowPages.com and threatening me with a $10,000 law suit if I do not because it says 'Use of Federal Limo name,logos or pictures must have Federal Limo Consent, violation will result in $10000 Fine.' on my contract.  I do not have a contract they cancelled it and last time i checked this is a free country with freedom of speech.  I am just stating the facts on what my experience was.