Indentation After Steroid Injection to Remove Hypertrophic Scar

Two years ago, I had a mole on my thigh removed by laser. Unfortunately, it grew back into a different color so I went to a different dermatologist. She identified as a hypertrophic scar, and said an injection would be best for it. She said it would flatten it out and did not tell me any side affects. New scars have appeared and I have a huge dent surrounding it. What should I do now? Will my dermatologist be willing to accept responsibility to fix it?