Thank you for your email.
I am very sorry to cause you into trouble, I will explain the additional charge to you.
This part of charge is normal and can not be avoided. Because the margin fees is received by Bank .Below is the three reasons for this problem:
Firstly, it will take the Cross-border royalties between Credit card issuing organization and Bank .
Secondly, the floating of exchange rate.
Finally, the currency exchange.
So the above three factors resulted in a little bit difference between your consumption and the actual charge.
If you have any other questions please contact me directly.
Thank you and best regards!