Indian model DSL-2750U, D-link (Indian) just upload new 'rogue' 'arrogant' firmwares on site as recommended to update, with absolutely no explanation, changes, less features, as well as very buggy, my $40 Router above model got entirely ruined by updating firmware as they suggest 2 years ago.
I don't know what you are trying to tell me there, but again D-Link does not care. And who is "they"?
You did not say where this router came from. As I noted above,
Either that specific D-Link is defective, or it is an ISP provided router that they modified. I suspect the latter.
In other words, you need to be blaming your ISP, not D-Link. The
manual for your router clearly indicates updating the firmware is a manual process. The manual also clearly shows how you can manually select your own DNS service provider, go with your ISP's, or even use D-Links.
So again, if you cannot manually make these changes, it is because that router is defective, or more likely, has been modified and provided by your ISP. So again, don't blame D-Link.
Also, you say it was 2 years ago. I note D-Link India has released two firmware updates since then, one in Jan 2017 and another as recently as October 2017, as seen
here.