I'm quite familiar with DCC processing of Mastercard transactions, how to avoid it and how to dispute it if it is involuntarily applied.. until this past week, when I have seen a strange phenomenon. My card currency is AUD, and normally if DCC was applied, the transaction would appear only with and AUD amount.

This past week I did a transaction in Hong Kong, to the value of HKD 322. This should have been converted by Mastercard as approx AUD 60.99. The offering on the slip was HKD 322 or AUD 68.45. Obviously we selected the HKD rate, however the amount has charged to the card showing the original amount of HKD 322 and the DCC conversion on AUD 68.45, as if the processing bank sent both amounts to my bank thus manipulating the exchange rate. As you can see all the adjacent transactions were processed correctly.

Has anyone seen this before, is this a new "escalatedly bad" implementation of DCC, where the DCC provider is now providing both amounts foreign and local to your bank? And any way to avert this, short of paying by cash? (The merchant didn't take Diners Club, and I don't have a forex-free Amex).

Looking for anyones inputs on this please... the receipt does not indicate who the acquiring bank was.

Obviously something strange is going on here... the merchant was a restaurant called Brickhouse in Hong Kong, below is my charge slip extract and an extract from my bank statement. Notice the x-rate on all the transactions that were processed normally in HKD on the same day..