That's too bad. I don't think I have ever had mis-labeled plants from the greenhouse. My problem this year was that the greenhouses had a very, very limited variety of veggies this year. It was really disappointing. Oh well, next year I plan on starting seeds in the house and make sure I have my favorite plants ready to plant outside when the temps are right.
It might help you to put your geographic location on your member icon. That way, someone from your area might be able to better answer you. I don't imagine my advice from northern Minnesota, zone 3b, would have much value to someone growing food in a southern state, like a zone 9a, for example.
FWIW, I did not have any problems with blight or sunscald, but I am way up here in northern Minnesota and it would be very rare for me to see any sunscald.