@Roy *******
you probably confused the 30 day extension you can get on either a 30 day visa exempt entry or a 60 day tourist visa, with the act of getting an actual tourist visa, which must be done before entering Thailand. Visas are used to enter a country, not to extend a stay once you are in the country. You probably didn't pay attention to the semantics and terms used. I am certain the Thai consulate did not actually say you can apply for a tourist visa once you've arrived in Thailand, and beyond unlikely that 100 YouTube videos also said something so incorrect. You just assumed extensions and a new visa are the same thing.