I don't know how scammers found out my phone number, but just now received a phone call from someone with American accent saying that the call is from overseas.
He proceeded saying something along the lines that my credit card number that had been entered into sweepstakes, was chosen to be among the finalist winners of some unnamed lottery. I guess for the ordeal to sound genuine he asked if I indeed have a Visa or Master card. I said "No." He went ahead reasoning with me that perhaps it must have been my debit card number then. I was silent. "Do you have debit card?" he proceeded. "No," I quickly replied.
Things suddenly became clear as water to him and myself. "Have a good day," he quickly hung up.