Unbelievable! I just came from the restaurant where I presented a Groupon. The waitress was nice, but a cook (or manager?) started making excuses not to accept it lying (saying that it was a discount of only 5$ when it was 15$) and later even threatening me.
He refused to let me talk with the manager/owner called Gilmar and lied again saying that because the limit of the groupon was for no more than two people, he would only accept it if I came with someone else. The folk barely spoke English, so I explained to him in Portuguese what "limit" means and he went BALLISTIC!
He started Cussing , saying that I was like other stupid Americans trying to bring stupid papers to eat for free, that he had bills to pay and that I was being a scammer (all in Portuguese, a language I speak for I am Brazilian-American). In one moment I really feared he was getting the knife to threat me! I tried to calm the folk down (the waitress also helped). I later apologized to the waitress for I didn't expected that her day would get so crazy because of the confrontation. Before leaving the maniac started explaining other workers that I was "trying to eat for free" and I then asked what was his name and If I could record his behavior. He went silent and I left. I never saw such behavior in a supposed professional setting. BEWARE!