Hello. I used to work in Thailand until earlier this year, and still have the visa in my passport with an expiry date in 2024. I am currently here as a tourist (expiring on thursday next week) and had an extension rejected - they said the previous visa was not properly cancelled, it didn't have a stamp from BOI. My previous company said they had cancelled it and gave me a document - which I now understand to be a general document from BOI acknowledging the fact that I would no longer be working for that company - and NOT in fact an actual visa termination letter.
Is it possible for me to go to Chamchuri with this document and ask for them to void and stamp the visa? Or do I need some sort of additional forms, documents, etc, from me/my old company? I contacted them but I got the impression they couldn't do more.