It’s not scarring. It’s hyperpigmentation, which is a common result of electrolysis and typical for people with brown skin tones like you. Hyperpigmentation is not permanent and will resolve after you’ve completed your schedule of treatments. It will probably even become less noticeable as you continue.
The hair you see is not regrowth. It’s new hair that hasn’t been treated yet. Because of hair growth cycles, you’ll need to treat the area many times over the course of 12-18 months.
Your electrologist should have taken you through the all of this information in a consult, so it’s disappointing if they haven’t done that.
You could try to use active ingredients like Vitamin C, Azelaic Acid and so on. It may help to reduce the hyperpigmentation, but don’t spend too much money as this is something that will resolve completely on its own.