The local town of Khanom has several ATMs and banks, a Western Union Bank http://locations.westernunion.com/search/thailand/จ+นครศรีธรรมราช/khanom, a Lotus Express and several 7 Elevens, drugstores, plus anything else basic you need - even a Top Charoen optical shop! 

Khanom has a few local markets in town including the Wednesday morning market and the Sunday afternoon market, where you can find a variety of fruits, veggies, fish and other local merchandise.