I've been getting this calls around 4am to 10am.... When I answered, it's just a "lady" saying "hello, hello"... I told her she's got the wrong number, but she keeps calling me!!!! She called again today  twice at 6am, but I didn't answer! One day I told her to STOP CALLING, but I think she got mad!... I'm really worried about this! Because, she just kept telling "hello, hello"! Like in a "weird" voice....