Let's Dance Ballroom

I purchased four private dance lessons (a $340.00 value). After my first lesson which was about 30mins. I was told that the Groupon lessons were only 20mins long. I was told they had combined the first two lessons and that at my next lesson I would be using the remaining two lessons. At the second lesson I brought in a copy of what I had purchased explaining that a forty minute lesson could not cost $170.00. My instructor agreed and said that their 40 min lessons are $85.00 (4x85=340) I tried again to explain that I just wanted what I had already paid for. So I left the studio. It was unfortunate because I would have bought a package if I hadn't felt scammed by the Groupon.