If someone said..

[ShadyLady53]

Yesterday (Tuesday), I arranged an appointment. The person said, “I can fit you in next Wednesday.”

Would you turn up today or on Wednesday of next week?

I would cancel the next appointment and tell them you won't be coming back to them and the exact reason why, and if your therapist has a manager or there is a business owner I would make sure that message was passed on to them. All this bad feeling for £8 isn't worth it, how would you be able to relax there again?

And that is why you should always (well, she should have) say "so that's Wednesday, 11th September, then?" to be sure with appointments.

I'd tell her to take a running jump with any kind of fee and don't pay it at all. And you can remind her that you won't be using her or recommending her to your friends either…

Or she gets real and sees you next Wednesday at 9am.

I grew up in London and I always take 'next' to mean 'the next one to come along'.
I grew up on London too, and it meant next week to me.

She has admired her mistake, so you shouldn’t pay for her dds breakfast club.

Next week for sure.

Next week.