Get online support
You say NBN Box. Are you on FTTP, with an NBN NTD fixed to the wall. If so what LEDs are showing?
Are you in SA? If yes, then there's a major NBN outage that affected the service.
This has been resolved and the service should be back to normal.
If you still need assistance, just send us a private message with your account details and we'll take it from there.
BasilDV