Well, I got an email back just now, & here's what it says...
"Remember that the blocks are moving around all the time, so you may need to check the shops more than once to find them all—a great reason to revisit your favorite shops!"
I certainly do think it's unfair, if you have continued to work through them in one day! I guess they don't give a rip if it's fair or not, & they must think we have nothing else to do with our time, right! Very irritating to say the least!