Waterfall guest house below par rooms

I bought my voucher from Groupon for the value of R2400 to stay at the guesthouse (Waterfall Guest House) for 2 days. I booked on the 19 November 2014 to redeem my voucher on the 08th to the 10th of February 2015. I was given a room that was not to the standard of the voucher. <br> <br> So we had a chat with one of the managers on the phone by the name of Cindy, we couldn't reach an agreement with the room, and we asked her if we can request a refund and she told us that we can request a refund.<br> <br> Groupon asked me to get something in writing from Waterfall stating that the voucher has not been redeemed. I sent emails to waterfall and also called them for an entire week but they refuse to give us a letter and we are now still without our refund.<br> <br>