As Don Haines suggested, I gave them one last chance. I actually e-mailed their firstname.lastname@example.org
address Tuesday after I had re-visited their shop, and earlier today (Thursday) the manager of the Henry's in my area contacted me. She let me know that they're willing to replace the focus screen, so I'm quite relieved about that. I doubt I'll trust them in the future with handling
my camera, but when it comes to buying stuff, I'll probably continue shopping there.
Btw thanks for the suggestion Monkeyhand. I'll consider them.