HDFC
Dupilcate note of Rs.500 from HDFC ATM

I withdrew Rs.1000/- from HDFC ATM from satara powai naka branch on Saturday 25th april.

the serial number is 3914.transaction time was 16:22.the demonitions received was one note of RS.500/-and remaining five notes of Rs. 100/- each.but the 500 rupees note was the fake one.

i came to know when i went to a medical shop and tried to make a purchase.

what should be done in this case?

please help.