My work permit was canceled on April 6th. I got an email from my place of work 2 weeks later notifying me.

I have not been to immigration. Is it safe to assume that when I leave the country on Sunday, they will be aware of my canceled work permit?

The extension of stay in my passport says June 6 is the last day and it says I have a Non-Re, whatever that is?

Your extension of stay ended the day your work permit was cancelled.

You are on overstay, be prepared to pay 500 baht / day in overstay fee.

Even if they cancelled your work permit, who's to say the left hand has been talking to the right hand, I am sure you will be able to leave, but if you want another workpermit with extensions of stay, you'll might have to pay up, this is not serious don't worry.

I prefer not to pay on exit if possible. The cost will be 15,000. Does anyone know if the "right hand talks to the left"?

I prefer not to pay on exit if possible. The cost will be 15,000. Does anyone know if the "right hand talks to the left"?

They will probably not notice.

But if you apply for another job in Thailand, questions might be asked about your old job and at that moment both labour and immigration might spot that you did not cancel your stay. So it might bite you in the back at a later time.

I prefer not to pay on exit if possible. The cost will be 15,000. Does anyone know if the "right hand talks to the left"?

They will probably not notice.

This is excellent news. You've got my hopes up!