Welcome to the Community!
We can see that the issue has been escalated to our Engineering Team and they have lodged it to Telstra for further investigation.
Based on our initial assessment, there is a line fault causing the issue, thus a Telstra technician was booked anytime between now and 26/May/2018 to check the lines outside. Your attendance is not required.
Our Engineering Team is monitoring the account and the case engineer will be in touch as soon as new updates become available.
Should you require any assistance, feel free to drop us a message. Thank you.