@crimex168 I am sorry to hear that you are in the same predicament as me but it is also good to hear that I am not the only one experiencing this issue.
TPG has responded to my query and are still looking into the issue. It seems to be a tricky one for them to understand where the problem lies but they have at least been very responsive and are trying to help. I have had a few different Support Staff get involved (and different Departments) and have been told that it should be de-activated as the account has been moved over to the rental address (which happened a couple of months ago now) but this may have been an assumption based upon the present facts. I notified the NBN Removal Team yesterday that the provider thinks that the line should be de-activated by now BUT the Relocation Team immediately checked and sent me back a screen shot showing that it is still "Active".
It is a little concerning that this is not a straight forward request and did not happen automatically when moving the account over to a different address as we can't have been the first customers to ever do this I would have thought. Maybe because the account was not actually physically transferred over but instead a new account had to be created, and the old one supposedly terminated, as a part of the TPG "Moving House" procedure?
I will post the solution on here once it is evident. But for now the TPG team are looking into it further. The last correspondence I had with them was yesterday when I notified them of the "Active" status as still being shown when checked by the NBN Removal Team.