got u just need claim before 31st thats all

"If you pre-order Reaper of Souls at a retail store—either a physical standard edition or physical Collector's Edition—be sure to redeem your Reaper of Souls game key via your Battle.net account on or before 11:59 PM PST on March 31, 2014. If you redeem your game key after that date, your pre-order loot will be consumed by the fires of the Burning Hells and lost forever. While you have six days from the time the expansion launches on March 25 to the time you must enter your code, to be safe, you should secure your preorder today and be ready to input your game key on launch day.