Yesterday I did experience an interesting bug.

From a lost position I did decided to resign and lost 18 points to my opponent. After doing this the game went on!? So I resign once again and lots another 16 points.

I reported the bug to chess.com. Though I don't expect much from them.

Due to this I wont resign in chess.com anymore!

it sounds like a very unusual incident.  I have resigned many times (oh, have I ever) and have never had the situation where I had to resign twice to end the game.  wait and see what administration says.  but to never resign again on this site may be a bit extreme, of course it's up to you. 

a bug? what did the chess.com staff say? i never experienced one..

This is normal. Your opponent was Chuck Norris.

This would be a better story if you resigned, but then came back to win!

Sounds fine so long as you keep playing. Sometimes when I get into a winning position, the other guy will just sit and wait for all of his time to run out. I guess it is not an issue if your playing blitz but I like to play 20 min games.

At this moment I'm still waiting for the chess.com staf to resolve the problem.

My counterplayer (the one who got 31 points for one game, we both had 1716) couldn't do nothing about it, he said.

Anyhow, due to this kind of bugs I'm pretty sure that resign won't be an option anymore.