It's so upsetting when this happens! It's been happening to me a lot lately, not with Mulberry, but with other things. That's the unfortunate part about online shopping. I hope you find something else!
Really sorry to hear you didn't like it! It does take a few days to 'break in' the EW - the strap needs to soften up and bend (mine was very very stiff) and the bag to sag naturally to lose that boxy shape.