What can travelers do when facing airline issues with Finnair during their travels to Thailand?

EU261 - compensation form on Finnair. Also claim hotel costs.

You should probably have a compensation claim under EU law if the change happened later than 14 days before the flight

They changed you flight by 21 hours I’m sure you are due compensation

Contact their customer service directly and file a complain (not by phone), send them an email or a letter (yes, the old-school style still works).

They have a specific department that handle complains, get their details and reach out to it.

They owe you money for the delay and inconveniences , it's written in black on white in their own policy guidelines (just like any other airline, they are no exception).

For each problem you get with an airline that is taken into consideration in their policy book, there's is a flat rate compensation you can get (again, no exceptions, it's an international travel rule).

If you don't ask, you won't get anything.

So just go and get that money they owe you.

Forget any customer service with Finnair.. had similar experience due to their flight change and a subsequently denied boarding in biz, as my Thai travel pass was now a day early. (By 20

Min). You are talking to an AI bot at the best. Hopeless, scandalous and making me always look for other options if possible #finnair (in case you are listening / interested in the effect of extremely understaffed and non working services )

Finnair, changed my flight from Bangkok I had to sleep at Helsinki airport never fly with them again

Known as one of, if not, the worst long haul airline as you've found out, sorry