What does pending mean in my Purchase-history?

I purchased three items for $ 9.99 on the 20th of this month through the App Store in-app purchase. However, when I checked the charge status of the debit card I selected as the purchase method, it was showed that only one item was paid. So I checked my purchase-history through the iTunes Store, only one of the three items was paid, and the other two are pending.

I thought it would take up to 2 days for the transaction process to switch from pending to completed, so I wonder if there is a problem with this. My debit card contains enough money to pay.

Here is the screenshot of my purchase history:

Please let me know if you have any answers or solutions to this situation. Thank you.