Up until a few weeks ago our VDSL has been running fine, about 70-80 mbps down and 28 mbps up.

Then suddenly the download speed has dropped to 6.3mbps but the upload speed is still good at around 28 mbps (according to speedtest.net)

Have called their technical support line many times over the last 3 weeks, each time being told that they have logged a fault and something will be done within 72hrs but when I call back nothing has been done.

Yesterday when I called they said they booked chorus to check it out tomorrow (today). Then late last night I got an email saying the fault was resolved (it wasn't)

I called back today and was told fault was resolved as chorus remotely tested the line as OK and they don't need to check it. 

Today they have sent out a new modem to test but I am not hopeful as I tested our old spark modem and its giving the same speeds

Is there anything else I can do or ask for; or do I just have to keep calling them everyday?

speedtest-

orcon supplied modem -

old spark modem -