It's a great lens! You can check out reviews here. I am very pleased with mine.
As for KEH's mistake, it may be worth calling and asking what they will do about it. I once received the wrong lens hood from them (just mis-packaged, mis-labeled or whatever), and when I called them they shipped me the correct one at no additional charge without asking me to return the old one. Now of course these lenses are more valuable than a hood, so the story may be different. And actually, the 45mm lens typically costs 2 or 3 times as much as the 165mm lens. But still, it doesn't hurt to ask.