I have no idea what happens to a ticket after the fact... but generally the airline doesn’t touch the ticket until it comes under airport control. All refund requests usually need to go through TAs. So even if you quote the correct PNR I’m not sure if VS will entertain your request for refund. All VS can tell you (if they want to) is - did TG request a refund and what the status of that refund is.
For a CC reversal - call up your bank and tell them that for the transaction dated XXXX for YYY amount etc. the merchant was supposed to reverse the charge. The merchant has not provided you the service or reversed the charge and you’re calling up the bank after numerous followups with the merchant asking the bank to reverse the charge. Your bank will then guide you through the steps you need to do to get the reversal done - there are some penalties as well if the merchant proves that the service was provided or reversal was done. You will need to provide documentary evidence, if you have responses from TG that will help your case greatly.
Which CC did you use for this transaction?