That depends on the card issuer. Filing disputes is typically a manual process since the common cases would be things like disputing fraudulent transactions or a merchant billing error. Presumably these things wouldn't happen to you often, and the card issuer wants to collect as much information as possible when investigating the dispute. Also, the infrastructure for the dispute process was established long before the time of online banking or even DCC.

Being based in China can be frustrating since it is among the worst - if not the worst - offender when it comes to DCC and being able to opt out. As a result, unless you relish filling out these dispute forms and your card issuer doesn't mind - certainly many on this thread enjoy filing DCC-related chargebacks - I would suggest for having strategies to minimize the chances of encountering DCC. This means using cash for smaller purchases or using Discover/0% FTF AmEx wherever possible. Learn which merchants have DCC and how to opt out of DCC with various terminals. Save your DCC battles for big purchases where you're more likely to get cooperation in trying to solve the issue (checking out of a hotel or big department store purchase) versus smaller purchase where the cashier doesn't care (coffee shop where you just got a $4 latte).