Who called from 2013838358

Left a message sounding confused and asking "Hello?" before hanging up.

I GET CALLS FROM THAT SAME # BUT THEY DON'T EVER SAY ANYTHING

Called noon yesterday and 9am today, no message.
Returned call, message was "requested free prescription card, wait for operator", but was on a number we DO NOT give out.
Operator sounded Asian, said OK when I asked to take number off call list, but never asked for number.
This is a scam operation.