Guild Wars 2

So i was running sorrow embrace exp and at the last boss, when he had no health left, i lost connection to the internet and when i reconnected the fight was over so i didnt get my tokens
what should i do

For now, Run the dungeon again.

Do another run to make up for it. Currently, the tokens are awarded for defeating the final boss, so if you miss that, you miss the bulk of your tokens. Sorry I don’t have anything better to suggest, but that’s how it is.

can i ask arenanet to give them to me

They can’t even return items for people who were hacked yet, so no.