TG just emailed notifying that they will cancel and refund the ticket.

updated with the email

Dear THAI Airways Value Passenger

Reference is made to your issued Bangkok - Stockholm v.v.ticket
on 18-19 December 2019. We have to inform you that there is
an extraordinary circumstance of erroneous distribution of Business
class fare during mentioned period because of a manifestly
incorrect fare.

We have to apologize for this incident. However according to our
ticketing policy we cannot accept these issued tickets.
Your tickets at the price that you paid are not valid for traveling.
In these circumstances we would like to advise as follows:
1. If you purchased tickets through Thai Airways official website
please contact TG contact center immediately to obtain
full price refund according to your original form of payment
and allow up to one billing cycle for refunded amounts
to appear on your card statement.
2. If you purchased tickets through an online travel agency
( or other agent )please contact the travel agent immediately
to obtain full price refund according to your original
form of payment.
3. Please note that the above arrangements should be made no later
than January 2 2020 17:00 BKK time otherwise your bookings and
tickets will be cancelled and refund will be automatically processed.

Again we do apologizing for any inconvenience caused. If you have
any query or would like to book your travel at the correct price
please do not hesitate to contact us at TG contact center
+6623561111 or Email : [email protected]

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