Based on your post history, you aren’t a stranger to booking mistake fares or trying to change them.
You may be receiving more “attitude” from AS because you booked the ticket knowing it was an error, and then continually called back despite receiving a fair offer that reprices a similar changed ticket to its value. They might not have been as harsh on a regularly priced ticket.
IMO you should just let this go as a hazard of booking an error fare and quickly book something that routes you away from China since avoiding the coronavirus seems to be the higher priority than this dispute.