What are the legal options to extend a stay in Thailand for 7 additional days after a visa exemption?

To legally extend your stay in Thailand for an additional 7 days past the expiration of a visa exemption, you can visit your local immigration office to obtain a denial of extension stamp. This process will grant you a 7-day grace period to leave the country, at a cost of 1,900 THB. Alternatively, you can also opt to briefly travel to a nearby country, such as Singapore, for a week before returning.