If you asked Thai for a refund and they said they will grant it, then you CC chargeback is unlikely to succeed, regardless of the timeline. TG is unable to make cash disbursements while undergoing the restructuring under bankruptcy law.
No! This is not how credit card chargebacks are working. Whether the merchant is bankcrupt or not - it does not matter. It is not the merchant (in this case: Thai Airways), who needs to fund a chargeback - but it is the acquirer bank (where Thai holds a merchant account), who needs to fund the chargeback.
That acquirer bank is bound by contractual agreements through Visa/MasterCard with the Issueing Bank (cardholder bank) to fund chargebacks.
In order to reduce the risks for the acquirer -> the acquirer is withholding a so-called "Holdback" from the merchant to fund future chargebacks.