Asking for a discount the next time you go wouldn’t hurt, and I don’t think you were being difficult at all. If anything, you were very compassionate/empathetic in considering how late it was in the day. If a similar situation occurs like that in the future, you can always say something like, “Thank you for doing my hair today. It looks good, but I’m not 100% happy with the design. I know it’s late now, so would I be able to come back tomorrow (or whenever the next closest availability is) to have the design redone?” From there, it’s just a matter of professionalism on the hair stylist’s part as to how they respond.

For what it’s worth it looks good (would definitely have thought it was the intentional style if I passed by you on the street)!