Inspirion 15 5570 slow WIRED connection, comparing to wi-fi

My ISP got 500 MBit which I'm indeed get ting on my mobile.
Inspirion 15 5570 Wi-fi is about 200 MBit
Inspirion 15 5570 Wired is ONLY about 60 MBits -  Way slower than the Wi-Fi!!!. While many of the Dell technician say that there is definitely an issue, Dell Advanced Resolution tells me that this is normal, and that is how the card works.
This is unacceptable makes no sense to me (after many Dell technicians have already looked into it at their lab and remotely).
Any advises before I take any measure?