I found no one to trust in Israel, I flew to Madrid, and glad I did. OK, my case is extreme, but I am highly satisfied.
I combined a vacation with the hair... now I do all my own maintenance and can order new units from my supplier. I will go back since I am considering a style change which will require a new template (larger coverage) and totally different density, curl, etc. I could probably handle it from here... but need a vacation.
If you are willing to go to London, I can refer you to my supplier, who has a salon in Central London (at the "W" hotel, I believe).