I've read through the forums but I'm still quite confused on my visa, so hope someone can give me some clarity. To begin with, I have been in Thailand for 2 years working with a valid work permit, but because of some real shady things going on with my employer recently I am going to need to quit without notice.

Reading other posts it seems as though if you have a multi-entry visa then you can stay up until the date of expiry, but if you have an extension of stay then you must leave the SAME DAY that you quit (seems insane).

My problem is that I seem to have both. My visa has both a stamp for a Non immigrant B visa multi entry 1 year expiring in October 2014 and an extension of stay stamp expiring the same date. In October 2013 both my old 1 year visa and my passport expired, so when I got a new one I had to pay a whack of money (over 6000 baht) to transfer it all over.

So in the end, if I quit tomorrow do I have until October 2014 or does my visa finish the same day and I must leave Thailand?

Thanks much.

I think you have a multiple re-entry permit, that goes with your extension of stay.

Yes, you would need to leave the country the same day, or apply for an extra 7 days at 1,900 baht. Don't forget to cancel the WP and permission to stay.