This has happened to me repeatedly at Thai places and it was honestly infuriating the first few times it happened. Luckily, I found out that at Thai places they usually have a spice tray they can bring out on request as long as you are eating at the restaurant instead of takeout. It became my common thing to expect to do so after my first bite when eating at places. At home I have my own dried peppers so I can make food as silly hot as I want.