I have visited London Retreat. Of the girls currently working there, I have seen Alex, who I can highly recommend.
I think that their rates are still £200 per hour.
For £150 per hour, there is a great lady who used to work there as Lisa and is now fully independent:https://www.adultwork.com/Sadie%2DStrumpet
She has her own play-pad and has just added a St Andrews' cross to her other items.
You can mix escorting, role-play and being dominated.
I am planning my third visit to her for this week.