I believe listed below is what should happen:
Usually a hold is placed on your method of payment for the amount you will be charging according to your purchase...the hold alerts your credit/debit card bank that a potential purchase will be enacted. So the bank places a temporary hold on those funds.
Then when the QVC order ships, on the day it ships you are supposed to be charged for the full purchase price.
Billing charges are supposed to be finalized on the day the item ships to you from QVC and then your Card/bank hold amount drops off, so all you should see from QVC will is your actual QVC finalized purchase charge.