Disconnected and lost

In my most recent game I suddenly lost connection with chess.com. It wasn't my internet connection as I was able to access other websites without issue during the downtime. Nevertheless, I now have an extra L on my account due to the time it took to regain connection (I "abandoned the game"), made all the more frustrating because I was clearly winning when the disconnect happened.

What I do is refresh the page when my opponent is taking longer than they should. 

So chess.com servers aren't garbage, and you don't get disconnected for no reason, so the problem was definitely from your end. If you're disconnected your connection bar near your username on the screen will start flashing, and once you see any sign of disconnection just refresh the page, that should normally fix the issue.