Huge inconvenience

I found a unit that I liked on Property24. I then contacted the agent who goes by the name of Gugulethu and I let her know that I’m interested. I app**** for the unit and everything went well (I was approved). I went to go view it and decided to continue with the process. Gugulethu then sent me the lease agreement for me to sign. I signed it and returned it back to her. I had also app**** with other agents for other units and they had also approved my applications, but after deciding to go with the unit I viewed with Gugulethu, I told the other agents that I found a place and that I’m no longer interested. After some days of silence from Gugulethu, she told me that the owner found someone else to lease to which has now left me with no place to stay. The agent prematurely sent me the lease agreement and made me believe that the unit is mine. She has inconvenienced me greatly and all she had to say was sorry.