Newly laid sod needs to be watered virtually every day. The problems you've described sound as if the new sod didn't get adequate water. You might be able to save it by watering the heck out of it right away and continually.
Dennis (cut2it)
C&onstructi&on C&onsultant
Over 40 yrs. as General Contractor for new const. & remodel - retired with time for you.