What legal action can you take against a beauty center for bad face treatment?

I was asked to help a friend find some representation, in an application of legal notice, against a beauty center in Dubai.

XYZ attended a facial appointment mid-Sep 22 whereby she suffered quite nasty chemical burns across her face as she undertook professional treatment.

Apologies were given at the time and XYZ was led to believe that this skin reaction/scarring was quite normal but, symptoms would elapse over a month or so.

9 weeks later and the burns are still present, considerably so, and much to her horror and disbelief. She is obviously very upset.

I wonder if anyone in this forum has experience in such matters to help/advise her on the process to take court/legal action against the salon.

This salon is clearly not following the correct procedure, and without further treatment to remove her scars, she now carries this for life.

I look forward to a few notes (perhaps on past experience) and the pricing structure of your fees, please.