Before everybody starts bashing a company for their sizes of UTH, think about this. That UTH she ordered is probably for a 40 gal tank, probably an aquarium style that would measure somwhere around 36L X 14W X 18H.
She probably has a 40 gal breeder style reptile tank which probably measures 36L X 18W X 14H. Before I get any UTH's I measure my enclosures floor dimensions and look for a size that will cover 1/3- 1/2 of the floor...
After re-reading the thread again I see that they sent you the wrong one, see if they will exchange it if need be...