Can I replace a 27.12MHZ by a 13.56MHZ Xtal on PN532
Some people told me I can replace it if the hz was a multiple. The
  fact it don't work as expect. Is it normal ?


Next time, better take a look at the data-sheet. The PN532 wants to see a 27.12MHZ xtal or external clock of the same frequency. You can't just pick a different clock-frequency.

You shouldn't have any problem finding the correct xtal online. They're cheap.