Brief Answer:
Depending on the type of acne marks/scars treatment can be suggested:visit a dermatologist for needful.

Detailed Answer:
Hello.

Thank you for writing to us at healthcaremagic.

I have gone through your query.
I would have preferred a few photographs to understand your problem better.

Acne marks can be either Post-inflammatory hyperpigmentation (PIH) Or they can be acne scars.

PIH is just a dark spot level with skin surface whereas Acne scars are irregularities that may be either depressed (atrophic scaring) or raised above the skin surface (hypertrophic scaring). Acne scaring is commonly, atrophic i.e depressed below the skin surface.

For Post-inflammatory hyperpigmentation (PIH), several pigment lightening creams are available on prescription of a dermatologist.
These creams contain various active ingredients like Kojic acid, hydroquinone, arbutin, azaleic acid, glycolic acid. They can be used once or twice daily at the affected area. I can see that you are already tried kojic acid based cream.

Chemical peeling is also an option for PIH; glycolic peel being particularly effective in fading excess pigment. Peeling sessions can be combined with topical treatment.
Sun protection is an essential part in the management of PIH and therefore, sunscreens add to the overall response by helping in fading PIH faster.

As mentioned previously, Acne scars are irregularities of smooth surface of skin; in common language scars are defined by various annotations like dents, pits etc
Various procedures that are effective in improving the cosmetic appearance of acne scars are chemical peeling, dermabrasion, fractional Co2 Laser, microneedling/dermaroller, subcision etc.
The number of sessions required are guided by the severity of acne scars. These procedures can be combined to produce better results.

I will suggest that you visit a dermatologist in your region. Your dermatologist will assess the severity of PIH and/or acne scars and advice you accordingly.

Regards

---