According to Vietnamese Immigration law, you can't apply for another eVisa while still in the country. You can cross the border to another neighboring country and apply for a new eVisa while waiting to return to Vietnam.
Another option is to proceed to one of their Immigration Offices to request more information regarding extending your current visa.
In the three biggest cities of Vietnam, these are the specific address:
- Immigration Office in Hanoi: 44 – 46 Tran Phu Street, Ba Dinh District, Hanoi
- Immigration Office in Danang: 78 Le Loi Street, Thach Thang Ward, Hai Chau District Da Nang.
- Immigration Office in Saigon (Ho Chi Minh City): 333 – 335 – 337 Nguyen Trai Street, Nguyen Cu Trinh Ward, District 1, Ho Chi Minh City.