Thank you for your pre-order!
Just to be sure, did you check your junk mail as well? The steam key should have been sent to you via mail after your order was processed.
If your charge is still pending, chances are that the order hasn't been processed yet. However, if the status doesn't change in a couple of days, please send an email to customer.niftyvisuals[at]gmail.com from the email address you have ordered with and we will get in touch with the payment platform. Thank you!