Who called from 4803449257

no one there hangs up when i answer

Had a call from above number. Caller knew my name and asked me whether I had reported them yet. I asked reported whom? The guy put the receiver down

I received a similar call; fortunately I noted the number and so rang back. No one answered the phone. Where are these people getting hold of our phone numbers and what is the purpose behind the calls? Are they ID thieves? Who should we report the misuse to?