I quit my job and left the country for ten days. While I was gone, my former employer cancelled my work permit (as expected). I came back in Saturday night on a 60-day tourist visa and was pulled aside by immigration because I still have a multiple entry visa stamp in my passport that doesn't expire until December 2017. The immigration officer told me that I need to go to immigration and cancel the multiple entry visa. Can you tell me where exactly I need to go and how long I can wait before going?
TLDR : Answer Summary
After returning to Thailand on a 60-day tourist visa, you need to cancel your multiple entry visa which is still valid until December 2017. The immigration officer advised you to visit the immigration office for this process. It's important to take the cancellation receipt of your work permit with you when you go to the immigration office, as it may be required to void any remaining permits or extensions related to your employment. Make sure to go to the immigration office as soon as possible to avoid any issues.