@Sâmia *********
There's no way to do that, sadly. Your only options is to either leave by September 26,
OR get a one year extension of stay (may be effective September 27),
OR *POTENTIALLY* (in theory) a letter from your embassy saying you can't leave Thailand (which may not be possible, depending what your nationality is OR if your immigration office accepts the letter).
Those are your only options, sadly.