If you use it for rental there is a location to put the code in. To use it for outlet you have to have a CS apply it to your account. It will show up under billing history or in your cart if you have already added things into it.
You are supposed to see if it will work BEFORE you place your order. Geez. Not to mention there is an obvious realization that some companies will shut codes down quickly if they recieve a larger response than they expect. Obviously they shut this one down already.