a 13-year-old indian girl faced with an arranged marriage has written a letter to her teacher begging her to stop the wedding .
she wanted the teacher to stop the marriage ` whichever way possible ' , the india times reported .
it is thought the ` oath ' duli refers to is the school 's promise she had to make when she started , but exactly what it included is not known that her father lachhu , who lives in gudibanda with duli 's mother , said child marriage was a common phenomenon in their society .