Why are there shipping fees on my monthly invoice???????

[spectralmedia]

Charged 31 dollars in fees on my monthly invoice for just 2 items shipped internationally, & no explanation on the invoice other than its a fee.  **NOTE I looked at the last 7 months worth of invoices, & March (newest invoice) is the only one with this "Shipping fees" on the invoice,  so PLEASE dont tell me "final value fees" is the reason because this is the 1st time I've EVER seen this on a monthly invoice. Ever..  

-Spec

PPS: I DO NOT USE FEDEX. I USE STANDARD USPS LABELS PURCHASED THROUGH EBAY