A woman asked to call on a no. 1800 121 170 170 to register the mobile number on this no. as they are advertising product of HINDUSTAN UNILEVER and they had set of target to meet, Requested to call and give OTP to register my no., it Is summer and and @ noon she came to in front of house, so as usual i gave her the OTP

But After searches i found that it was fraud......

What to do?