Can I obtain a re-entry visa at Patong Immigration or do I have to go to the main office in Phuket Town?

You can get a reentry permit at Patong, Blue Tree or Phuket Town.

i thought there was a reentry permit desk in Phuket airport after you check in with your airline (as its an international airport) unless its now gone You just have to go to passport control to the left side corner booth near the Immigration office from memory if someone whos ben recently can confirm

I do not know, but lets see if people in Phuket can help you out.

btw it is not a visa but a re-entry permit,