Returned faulty 4gx modem disappears at TDC

[Herewegoagain1]

I received my new Hauwei 4gx modem when I switched from iinet nbn to Telstra  mobile broadband but after a lot of mucking around for a day and a couple of tech calls I concluded it was a dud as wifi signal level varied constantly and the range was terrible - 80mbps download speed if next to modem and 20 if one room away and signal so bad security cameras and repeater wouldn't  work unless in same room. The old nbn modem worked fine over whole house and yard from the same spot.   

Anyway I was told to use self return process to post to TDC.and  It arrived according to post tracking last week but using the TDC tracking tool it doesn't exist. Does anyone know how long these people take to repair or replace anything or even record the return in their systems for tracking. I am currently without a broadband service  or device that I paid for and fear that the modem has disappeared into an endless pile of faulty mobiles etc. 

With another carrier I had a device replaced immediately and a reply paid envelope for the faulty return came with replacement modem and I was up and running in 3 days - Telstra doesn't seem to work that way!

[Jupiter]

If you provide the tracking as evidence that it was returned, then the process should be sped up (for a replacement, but if it is a repair job it takes about 2 wks).

[Herewegoagain1]

Who do you contact? Bottom of tracking page says email TDC for queries with no active link to do it - hopeless. I can prove tracking via Oz post that it arrived but using sim phone number or imei to track and not on their database. Can't search on oz post number on their system. Hard to expedite if no number or email address to contact them.