For the past 25 years I have worn nothing but Reebok athletic shoes--in a size 5 1/2.  That's what I ordered, that's what the shoe was marked, and I could barely get it on.  I suspect these are "seconds" or, in this case, Amazon and Reebok's quality control leaves a lot to be desired.  To add insult to injury, it cost me $4.98 to ship it back to Amazon.