Well, if the flight is cancelled, you are supposed to get at least 250 EUR in compensation. That's around 75-80k miles, i.e., about the amount you would expend for that flight, anyway.
Lufthansa and British Airways do credit miles for cancelled flights automatically. (Fortunately) I have not had the experience of cancelled award flights with airberlin (yet). They should do the same. If not, file a complaint here:
https://www.airberlin.com/en/feedback/complaint
Cheers,
--j.