If you fuck up, but then actively and successfully make up for your errors, there's no hell or punishment awaiting you. Big part of satanism is self-betterment after all. It would be counter-productive if people were punished for small mistakes instead of having the chance and tools to better themselves and make up for their mistakes.
Most of the time people punish themselves through the consequences of their stupid actions or decisions. Treason is the only case I can think of when the old gods will actually intervene.