Letting clock run out on loss

Can there be a report button for this type of behaviour? I run into it way too many times, I win a game with the first 5 minutes and my opponent decides to be a sore loser and let his 25 remaining minutes run out. I get that people should be given all the time they have for their move but often it's obvious they already gave up, especially after losing a queen or rook early on. It's quite deterring from enjoying the game to be honest... 

Especially at the low ratings, like... it's just a game, learn from your blunders and make sure you improve next game. 

I was just saying to someone this morning...

You know what is never discussed in the chess.com forums?

No...what?

No one discussing letting the clock run out, and how to report it.