Commentary for Kiddushin 79:20

Profaning God’s name is considered to be worse than other sins, and one receives no “credit” in this case. One interpretation of “credit is not granted” is that God does not act like a shopkeeper and delay demand for payment. Rather, he immediately extracts punishment for profaning the Name.
Another interpretation is that if one has committed this sin, it tips the scales if one’s merits and sins are equally balanced.