What should I do if I've been fired in Thailand and what happens to my work permit and visa?

Hey everybody! I know it is not a 100% visa relevant question but can anyone point me to the right direction/group where I can ask what to do when your empoyer for no true reason decides to fire you from one day to another, is there a rule that you have to immediately return your WP to the company's accountant for cancellation? Not that I would need it of course, and I am aware that I could not work with it, but it has my picture my personal data etc.and as I had to pay for taxes and my visa run in vain in return of absolutely NO payment not even a baht, but lost a lot of money, energy in the process I would like to know whether I really HAVE to do it immediately or I can sit on it at least for a few days to piss off my ex -employer, who is clearly the most disgusting human being I have ever encountered. Also, in this case what happens to your visa? I was talk by the accountant that my last stamp is valid so I can stay in the country until that date. For this latter question I would very appreciate to get some confirmation from this group. Thank you very much! Have a lovely day.