Serval Calls a day. You pick up and no one is there

Caller: 0489 994 755

Only rang once then hang up

many calls from this number, each time you answer there is just silence and it hangs up

they call two to three times daily, on weeknds from 6am in morning and sometimes 9pm at night. first time I answered i could hear someone there, but i had to hang up as no one spoke. i didnt answer any other call from that number ever since. wish there was a way to stop them constantly calling!!! Grrr

no one answer when i pick up the call, u can hear the background is like call centre feeling