The difference in customers is just the description. I receive from the Amazon Store owner $9.80. So that balances, the issue comes in with the shipping, which is $5.75 of the 9.80. So my net is really $4.05 (12.44 - 1.87 - .77- 5.75). Paypal is credited 9.80, so if I show the -$5.57 shipping on the receipt, the Invoice balances out, but the Paypal account will show an outstanding due amount of $5.75.
This shows the shipping deducted:
Here is the paypal account showing the credit when the shipping is subtracted as above:
Here is when I withdraw the $9.80 from the Paypal account and transfer it into another business account:
On your example the $2.64 are the commission fees due to Amazon and the Store owner and are removed from the total 12.44 prior to the Paypal deposit to me. Those are accounted for in the receipt.