Oh dear, that sounds like a bug!
First, double check that you are looking in the correct place. There are 2 places to view your orders, one is public and one is private.
Your 'Purchases' tab on your profile
If you set your purchases to 'private' nothing will show up in this section because this is the place where your friends and followers can see your purchases.
Your 'Orders' section
This is where you can privately view your past orders if you have a Storenvy user account.
If you create your user account after you place an order, that order won't show up in your account.
If you have placed an order since creating the user account and it isn't showing up here, that is a glitch in the system but it doesn't mean your order wasn't placed. If you have an email from us confirming your order, then it definitely went through.
If you also got a confirmation email from Storenvy then you should be fine. If you would like an update on the status of the order, just contact the store.
If you didn't get an email from Storenvy, please let us know so we can double check if the store knows about your order and make sure they process it for you.