I encourage you to report to the Managers. The team at No5 seem to be pretty professional and good to deal with in my experience. But they can't fix what they don't know about. Where 42G may provide a discount off the next visit, I haven't seen that done a No5, which is a pity as, if not rectified, disappointed customers may not return - and that's a loss of business. But nor have I personally had any really bad experiences.
My impression is they seem to ask almost every customer about their experience on the way out, especially new girls. So, they compile collective knowledge about their girls very quickly.