Hi Kel,  I found a wonderful post in the Fitness Dash forum with a strategy on how to beat that level by Pinky1130. I suggest you take a look at her answer. It looks like a good one.  Cait :-)

Did you buy this game in a store?  You said you checked in the box for papers so I thought maybe you meant that you purchased it in a store.  I didn't know you could purchase WD2 that way but if you can, then it changes things. 
 
If you installed the game with a disc you purchased I don't think it would ask you for an unlock code.
 
If you purchased it online from Playfirst then do what the other poster said and look in your account settings area for the link that tells you your unlock codes for games purchased.
 
If you did indeed buy a boxed version in a store then I think something is wrong and you need to email playfirst for help. Try support@playfirst.com or click on the link at the top of the page for a help form.
 
Cait