It's obvious they want to extort money from you. By law, you're not required to pay! But you should pay because they're the ones who decide whether to grant you a visa! There's a rule of life that says when you're the hammer, strike; when you're the anvil, stay put. In this case, you're the anvil and they're the hammer.
now I am in Thailand with a tourist visa! Tomorrow I will get married with my girlfriend! I live in udon Thani and I want to apply for marriage visa in vientaine but I can't book an appointment on line! What can i do?
You must understand that Thais are taught from a young age in schools that they have a duty/obligation to take care of their parents! they do a kind of brainwashing to them! It is a cunning and sneaky move by the Thai government to offload elderly people to their children so that the government does not have to take care of them with social pensions or other types of benefits