There are not many foreigners in Pang Nga in Southern Thailand. If you are one of those then you are very unique. The contact details for Thai Immigration in Pang Nga has been listed below with a map and contact details of the office.
You can extend a tourist visa at any of the Thai immigration offices in Thailand just at at the one below. As stated there are not many foreigners in this part of Thailand so we don't know how foreigner friendly they are. There are a number of other immigration offices int he region so check the listings got Thai Immigration in the Southern Thai Provinces here – See also Thai Immigration – South
Thai Immigration in Pang Nga
37 Moo 3 Amphoe Mueang