No disrespect intended
@Frank-******
BUT just because you had a born, bred, rice-fed thai speaker there doesn't mean there wasn't a "lost in translation", Most thais don't know ANYTHING about visas/extension etc and would take any b/s story an immigration officer told them as gospel (because thaiz are conditioned from birth to defer to what a thai in uniform says)
I think you just got a cranky person.
I went back and looked at some C/M covid extension stamps and it appears (at least from what I see), they are adding the new 60 days to the expiration date of your current stamp.
Dunno why they didn't for you, sorry about that