Asking for divorce and blackmailing me to give 1 lakh

Arranged marriage is mine . I am an orphan and very poor .Before marriage they gave me 1 lakh for marriage expenditures they forced me to take. After marriage she told me on marriage day itself that she does not like to have physical relationship with me .I asked her parents and her brothers what was the problem she had ?.They asked me please give some time to change her,i gave nearly 9 months but she has not changed. Her parents and she hidden the truth that she don't want to have marriage life. Finally they nicely said we can take divorce .I agreed but they are black mailing me to pay 1 laK