Two ladies came to my house as sales woman dressed in Hindustan Unilever Limited employee with ID Card and selling the vaseline product of company. They said please help sir we are poor and we need to provide the proof to company that we came till this locality for selling this product. They took my phone and dialed 1800121170170 and after that one OTP came and they filled in their phone number and went back. I asked the purpose so they said it is needed to give them a proof about that they covered till this locality for selling the product.

Can you please help me what information i compromised by giving them OTP which came after calling 1800121170170. What precaution now i can do to save myself from this fraud. Please help.