I'm in Thailand, but not in Bangkok. Is there a closer to Koh Samui place to get a Chinese visa?

I'm a US citizen, staying in Koh Samui for a few weeks. I only got a stamp in my US passport, at the airport when I entered Thailand - no special one.
I'm going to PRC on a tour in a few weeks, and I don't want to go back to the US just to have my Chinese visa done. Bangkok is far. Is there a closer place to get it while vacationing in Thailand?