You should read the information posted on the official website on the Order page. It says that the product should arrive in your inbox in 48 hours. If that doesn't happen, you will have to contact the developers.
Order page: http://dts8888.com/order.htm
Tip: Check the SPAM folder because their email might be in that folder as well.
Send them an email to check the status of your order:
Note: Ignore the fact that they don't offer refunds. If you don't receive the software, you can use PayPal to dispute a chargeback and you'll get a refund eventually.