I should know better, in a hurry, and did not look at a second check-out invoice that switched the credit card currency from yuan to dollars. Just as bad, the charge to my Chase IHG credit card was paid as purchase to a Chinese real estate partnership, not an IHG hotel property, and I'll now have to write in to Chase to get my 5x points for IHG stays credited.
Needless-to-say, I am angry and disappointed that an otherwise good stay is ruin by a cheap con-game at check-out.

I won't be back. The nearby Conrad is priced far more reasonably, and did not cheat me on my stay the night before the IC.

UPDATE:^
I received this follow-up from the hotel:

"Unfortunately upon your departure the Front Desk charged your bill from local Yuan to Dollar without notification. Please accept our sincere apologies for this, we immediately contacted Bank of China to correct the transaction. Kindly allow it processes in another couple of days done which the USD15.7 rate difference will come back to your bank account soon. You are our IHG top loyalty Platinum Ambassador, your comments are truly and extremely important to us. For our hotel always claims to deliver a “hassle-free” experience but obviously it failed to you this time. I do hope you could give us opportunity and will still consider we are a right place to enjoy despite this matter. We will definitely use it to fine tune our operating procedure and keep continuous improvement. We wish to welcome you back whenever your travels or business brings you again to Beijing..."

True to their word, the DCC charge was refunded.

IC Saniltun is an amazing property. I was upgraded to a corner Delux room, which is more like a junior suite. The room is modern and high-end in every way without being ostentatious. F&B is fairly priced by IC standards. The Tapas Bar restaurant served an outstanding served-in-the-pan paella. There are some room rate price-for-value and location concerns (pole dancing girls aren't my thing), but I would not cross the property off a future stay list out-of-hand anymore. ^