When you "purchased" the pre-order voucher your CC was not charged.  They sent you a pdf file with emedded links and a download for early adopter badge.

Download the pdf file.  When opened, you are asked if you puchased directly from SMS or from CP.

If you purchased from Smith Micro click on the link.  If you purchased from CP, click on that one.

I didn't need to enter the voucher code because I purchased from SMS directly. 

If you click on the link and have to log into your account, log in and click on order history.

You should see a listing for pre order voucher for whichever version you ordered.

Click on the order number.  You should be taken to a shopping cart that has the app at the pre-order price and the EDS.

If you don't want the EDS, click on remove.

Go through the checkout.  This time, you CC is actually being charged for the transaction.

Pre-order vouchers must be redeemed by the end of the month.

If you didn't buy the EDS, you still have 30 days from the date of purchase to d/l your order.

If you purchased pre-order from CP, you will need your voucher code.