$100 dollars extra on my bill because the power supply for my WiFi router failed?!

A couple of months ago, my WiFi router suddenly had no power. I figured the problem was most likely the power supply.

After I spent the hours that it takes to wind through the online and telephone support processes (had to try both and I don't remember which one finally worked) I was told that a support technician would be sent out. Now, it's possible that someone told me at some point in the process that I would have to pay $100 for that, but certainly not well enough for it to stick in my mind, so I was surprised to see that I was charged an extra $100 (on auto-pay) on my next bill. I then had to I wade through the website to find where to see past bills to find out why (that wasn't TOO terrible, but it's just enough out of the way to feel like you're trying to make it inconvenient to get to).

So, given that the problem was obviously likely to be the power supply, why wasn't the first recommendation that I bring the modem and power supply to an Xfinity store to see if a different power supply would power it up? Why, instead, was I told that a technician would come out that I would have to work my schedule around an pay money for, just to confirm that I needed a new power supply and swap it?

Also, the amount of time it took me to work through the support system was a whole lot more than the time the technician spent on the problem, even accounting for his travel time. Why is MY time not worth anything?