promotional call

I am a boy. I kept getting calls from a unk nown number. I have been getting calls for the last three-four days, I did not answer the call, then I answer it again, then I hear a ringtone nearby, why does it say that your recharge is over, whereas I am recharged, it says that you can check from the otp that you tell me otp . And 10 lakh rupees are withdrawn from my account.