I am sorry, and understand your stress,
checked with NBN, They held your installation
The reason I received From NBN-
"The planned remediation work for this Held Order has been identified as requiring a planned outage in order to be completed. This is likely to impact multiple active services in the area, and as such, under the Planned Outage Reduction Plan,"
Unfortunately, we have to wait until NBN fixed the Network.
And changing isp, will not going solve this issue, our NBN team keep forcing, NBN to get this network issue to be fixed.