First, that bill. Contact your credit card issuer and ask for the detailed billing. If that doesn't give you an idea what the bill was for (valet parking comes to mind as a possible additional fee), contact the Four Seasons directly and ask for a copy of your updated folio. If a bill was added after checkout they should be able to scare that up for you.
I'm really surprised you've had two problems with the Four Seasons Seattle. When friends come to visit that's their preferred hotel since it opened, and I've never heard negatives.
Second, the best way I've ever found to stop DND problems is to call the desk and request housekeeping while I'm in the room. I usually travel with a pet domestically, and the last thing I want is my cat (or dog) getting out in a high-rise hotel in the midst of a city. ANY animal can get out of a crate or an ex-pen. Most cats won't come to a stranger. Loose kitty=poof!
If you know you're on a different city's schedule, making the same desk call can get you some more sleep when you want it. Ask what time housekeeping starts daily WHEN YOU CHECK IN. If they start at 6AM and your internal alarm says 'sleep now,' ask if you can be first on the list. You're done working and are ready for bed. Usually, all I want are extra linens (especially washcloths and hand towels), and creamer/tea for the in-room bev maker. I don't need vacuuming. I don't want the air freshener. And I'm not a pig to totally destroy the bathroom and tub if it isn't cleaned every morning. What I want usually takes less than three minutes for a housekeeper to hand over, he/she keys the door to 'done' and we're all happy. Sleeping through the other rooms being cleaned and various people checking in and out all day (and the attendant noise) will still be a problem, but at least your door shouldn't be opened.
Hotels do have electronic means to tell if your room has been cleaned (it's part of the electronic lock system); if it shows not done after a certain time, the management often takes it to be the housekeeper's fault. To avoid this, many maids do ignore the DNDs. They don't want to have too many warnings, or they're afraid they'll lose their jobs!
I played do-si-do with an overzealous housekeeper at an Embassy Suites 18 years ago, and she finally told me about the door lock thing. Now that I call the desk and politely request my room be done only when I'm present and-could-you-please-get-to-me-soon-or early-or... now?, I no longer have to go about calling 'kitty,kitty' in the stairwells.