Patrols--campaign still going ? Not sure

[XenonSurf]

Originally Posted by AP514

Hum sank 2 DD's and a tanker..got Zero points.....

If they are not reported in your Captain's Log with a tonnage, then - technically - you didn't sink them
Maybe they have sunken because of rough weather? In that case you don't get any credits, sorry.
Another reason for not receiving credits: You did sink them in the past and got credtis, then you reload game, and meet again the same ships (can happen, depending how you play), in that case > 0 credits the 2nd time