Hey, SubmitHub founder here. Sorry for the confusion. You get two types of credits: standard (the 2 you saw) and premium (which you have to buy). Your standard credits refresh every 4 hours (assuming you use them).

When going through the submission process you'll see it prompts you whether you want to use your standard (free) credits or premium credits. If you don't have any premium ones -- and don't want to buy them -- make sure you stick to the 'standard' path.

The core idea behind SubmitHub's "model" is that for decades it's been near-impossible to catch the attention of bloggers/playlisters/curators/whatever. Our system dangles a carrot (~$1) in front of them to guarantee a response+feedback about your song (with the ideal outcome of course being that they share your song - no additional costs involved).