Dear KPN,
I think KPN is cheating people by promising higher speeds while the actual speed is lower.
I pay for a connection of 50 Mbps, but if I measure with a wired connection, I get a maximum speed of 36 or 37 Mbps.
I had a T-mobile connection before KPN and used to easily reach 52 mbps, but that is not the case with KPN. Can you check here what the problem is?