Can I extend my single entry B visa in Thailand, or should I apply for a new one in a neighboring country?

The user is inquiring about the possibility of extending their single entry B visa currently valid until January 12, with a permit to stay until January 15. They seek advice on whether an extension is possible and the procedures involved, or if they should consider obtaining a new visa from a neighboring country. A comment suggests that the user may only be eligible for a 7-day extension and indicates a fee of THB1,900.