No, my credit card print outs that I signed were all in RMBs not C$s (though one of them was booked as a SPG $s and pts at US$60 per night it was billed in RMBs not US$s too). Hotel charges were Amex, so not sure how they do their conversion and I believe there is a percent or two tacked on. The credit card advance was a HSBC Mastercard.

The SPG hotel (le Royal Meridien) was RMB2,979 which converted to C$549 or US$440, which works out to be 6.77 to the US$1. I also noticed in my IC conversion above the C$ to US$ should have been closer to US$300. That would make the conversion from RMB 6.74.

BTW I doubt that the DISCOVER card would be honoured in China. It is pretty much a US credit card and not accepted very widely, not even up here in Canada.