Hi @tina51 ,
What is the model number of your phone?
If it is a Uniden Dect 1760 to turn off the light:
''With the phone in standby, open the menu and select Global Setup; select VMWI Reset, then select Yes.''
Is the phone connected as a VOIP phone service on the NBN?
If it is then are you sure that Messagebank hasn’t been turned On? By default Telstra turns on Messagebank when on the NBN.
What do you get when you dial 101?