Hello,
Local Dlink support agreed what I am reporting is impossible, and told me to avail of the warranty. I did, and I just spoke with the tech who was testing my router. He claims the router has been working since yesterday and he's getting 80 Mbps on LAN, and 30-40 Mbps on WiFi. Claims everything works fine and there's no problem with the router.
I guess that even though I am paying for fast internet, and fast 300 Mbps external dual antenna wifi adapter, I'm still not gonna be getting anything more than 20 Mbps wifi and 40 on lan. Seems there's no way to convince them it doesn't do its job.
@ FurryNutz - I am much obliged for your assistance in this matter!
Best,
T.