Travel agency cancelled my accommodation!

Every year, I visit Knysna during the Oyster Festival in July. Knowing how popular the festival is, I always book well in advance. I booked Tides End Townhouse in Knysna for the period 03-07 July, with Mark Calvert at Sedna Travel on 24 February and paid the R1000 deposit. Two days prior to my arrival, I contacted him to check if everything was in order. He told me that there might be slight problem, as the owner of the Townhouse took the key with him and will send the key via courier. He told me that the key might only arrive on 04 July and suggested we look for alternative accommodation. I told him that this was not a possibility, as it is the Oyster Festival weekend and from past experience I know that accommodation would be fully booked. I suggested that he should get a locksmith. He contacted me back 1 day prior to my arrival and said that the owner no longer wants to give the townhouse to us for this weekend. I asked for the owners number, but he refused. I explained to him that it will be virtually impossible for me to find accommodation at this late stage. He was very unapologetic for his error! I spent 2 hours to find alternative accommodation at triple the price.