I think that you and this tech have different ideas about what your amp should sound like. Most Marshall owners would kill for the setup you have now, but that's not what you asked for. Hardness 7 is way higher than Groove Tubes usually recommends. You probably had to insist that you wanted 7's, not 4's. I had the same hassle when I retubed my Ampeg VT-22 with new 7027A's.

You will have to get your tech to understand that you are paying him for his ability to fulfil [u]your[/u] requirements, not his. Some techs get a 'Guru Complex' that puts their ego ahead of your specifications. Be polite, but [u]firm[/u].