I guess the problem is solved.
I was connecting to the dap and not the router, why shall I connect to the dap and leave the router, the dap (current) function is repeater, in other words, in the repater mode and not in AP (Access Point) mode and the router Wi-Fi is repeated and strengthened, so everything is running as it should be.
This following YouTube video showed me my mistake, it's from D-Link India
https://www.youtube.com/watch?v=M3nkZAkcoJk
The dap is working flawlessly and I've upgraded to the latest firmware found here https://support.dlink.com/productinfo.aspx?m=DAP-1665
Thank you so much dear FurryNutz, extremely appreciated sir.
Your replies at this topic (http://forums.dlink.com/index.php?topic=59973.0) and here have helped me a lot, thank you so much

Wish you all the best,
Hesham