When a Thai baby is born they spend their first years learning Thai and after about four or five years they are fluent. What's the difference between the Thai baby and the university student? It's obvious ... Thai babies are smarter.
How often does it happen that a baby born in Thailand has a Russian accent or a baby born in North America a Chinese accent? I've never heard of any cases. Why after the same time spent "studying" do Thai babies speak fluent Thai and university students do not?
At Payap University, as at most schools, you are expected to speak the first day of language class. You are expected to speak and listen to your classmates. Thai babies listen only to the perfect language model - the native speaker. They listen and only listen. How can Payap University students be expected to learn a language when they're expected to speak on the first day of class. Or when they listen mostly to non-native speakers?
If you want to learn a language you're unlikely to do it in a classroom - especially a Payap classroom.