Vitamin C is never a good cream for pigmentation.
Vitamin c is mainly indicated as an antiageing serum, as a glow serum, etc.
Reduction of pigmentation and spots require skin lightening agents such as arbutin, kojic acid or niacinamide. Look for these ingredients in your cream.
Next Steps
if this does not work out. consult a dermatologist for the same. yiu might be prescribed skin lightening creams, q switch laser or spotless peels for best results
Health Tips
always usea sunscreen. DO NOT USE OVER THE COUNTER STEROID CREAMS.THEY ARE POISON FOR YOUR FACE