I have used three different services for case study work over the past two years across different modules of my MBA program and the variation in quality between them was significant enough that I think sharing the specifics is actually useful rather than just offering general advice about vetting carefully. The honest truth about finding a reliable case study writing service is that the evaluation criteria most students start with — price, turnaround time, website professionalism — are almost entirely irrelevant to predicting output quality and the criteria that actually matter are much harder to assess from the outside.
The first service I used produced work that was structurally correct and completely analytically hollow. The case was described accurately, the problem was identified clearly and the recommendations section read like a list of things any intelligent person might suggest after ten minutes of thinking about the situation. There was no theoretical grounding, no evidence based reasoning and no engagement with the specific analytical framework my module had been building toward all semester.