I'm sorry to hear you went bust, what limit were you playing?
Anyway, this doenst help the other problem...
Open your client or log in the site, then select Bonuses, will open a page like this one:
On the bottom you find all the active bonus, click on the View More button below your bonus (if still present and not removed as you busted). There will tell you condition for release and how many points you reached.
It might actually happen that bonus was not active for some reason and as such you havent unlocked it for that reason.
If you see in the above image you have 2 bonuses, the below one has in the top right corner a sort of Play button, that means that the Bonus is there but not active, I will need to press that button in order to collect the points, while the top one as a Mark sign whih means that the bonus is active and I'm collecting points for it.
Have a look how you stand and in case contact their support.
As you went busted my suggestion is to review your playing, calm down and start playing their freerolls, within the first months you have access to all the Bank Roll Builders and is quite easy to go ITM, if you apply yourself you could easily get a few bucks back to invest in NL2.