Are you sure you have marks (which means dark spots) or scars(which are permanent depressions in the skin? Marks fade relatively quickly...for the scars procedures like microneedle rf or dermarollers or lasers help. Scars take a while to reduce..And they reduce only my 35 to 75% depending on how deep the are. 100% disappearance of scars is difficult to achieve. So figure out what exactly is it that you have by asking your dermatologist. And discuss it out with him/her. I am sure you will get your answers.
Next Steps
If you have active acne then only treatment doesn't work.Start modifying lifestyle : sleep by 10 pm wake up 6 am EXERCISE 60 min everyday and eat a Balanced diet ON TIME. This helps in the treatment.
Health Tips
Read these 2 articles to get an idea of what I am saying. 1. http://www.skinmatra.com/single-post/2016/09/17/Listen-to-your-skin-talk-Here-is-how
2. http://www.skinmatra.com/single-post/2016/08/25/Want-Glowing-Skin-Read-On