สตีฟ เตเต้ Okay, International drivers PERMIT. Still, you can only get an International drivers PERMIT in the country that issued your drivers LICENSE.
Since the OP stated that his drivers LICENSE from his home country was out of date and thus non-existent, he asked where in Chiang Mai he could get an International drivers PERMIT because he does have an drivers LICENSE issued from Thailand. Do you get it now???
Then they did something wrong as personal goods are exempt from import duty when shipped and arrive within the first 6 months of your relocation. Talking from personal experience a few years back. I doubt this rule has changed since.
You can obtain an international drivers license as a foreigner issued by Thailand. But you need to carry the (Thai) 5 year license. You can't get it on your first 1 year license.
You can also just book a cheap flight with a budget airline to one of the neigboring countries. As long as you show a flight out of TH it's okay. Don't need a returnflight to where you come from.