Misrepresentation and took my money

So I am a J1 student who booked my tickets through Janita Janse van Rensburg at the Somerset West Flight Centre outlet. I confide all the information to her, telling her that I will be working as a J1 student in Miami for a year. After the year I get a one month leniency period to travel the states. I asked her if this will affect my return ticket as I left South Africa on the 9th of September 2014 and will finish work on the 9th of Setemper 2015 giving me a month to travel so I will be leaving the 8th of October 2015. She told me there will be no problem. I can move my return ticket to that date. So I paid R15000 for my all round tickets. So it came time to change my return ticket to the 8th of October and now Flightcentre can't help me. They say I will lose all my money I already paid. The ticket and the money is going to waste. Thank you Flight Centre for taking my money and not even trying to refund me my money. Thank you for the misrepresentation and that I beieved I could trust you with my money. Thank you for taking my money and stranding me in America.