People can be equally stupid sometimes.

I once reported to an ISP that I am sending router solicitations, but I am getting no router advertisements back from you.

Eventually they sent a technician to look at the fiber box (even though evidence suggested a 99.9% probability the flaw was on their side of the connection).

The technician disregarded everything I had reported about the problem, hooked up his own laptop to the fiber box, and ran some speed test, and then concluded everything is working.

So I stated something along the lines of: I don't know what you are doing on your laptop, and I don't really care either. What I care about is that you are not sending any packets whatsoever when I hook up my laptop.

So he called somebody and I ended up talking with somebody else on the phone and explained again that I was sending router solicitations, and they were sending no packets back to me at all.

And now we get to the point where it took a turn for the worse: The guy on the phone now claimed he could see that my laptop had never sent any packets to them in the first place. I said then he is looking in the wrong place, because I can see the packets being sent.

So he asked me if my MAC address was (read out the correct MAC). And I confirmed. And he then said, yeah, we haven't received any packets from that MAC address. So I politely explained to him, that obviously they have, because otherwise he couldn't know my MAC address.

And he proceeded to make up some story about their equipment being able to see the MAC addresses of devices even if they never sent a packet.