I will start studying at a Thai university which requires me to get a Non-ED visa. Currently, I was doing an internship with a German company (employment based in Germany) and business trips to Bangkok and other SEA countries. I already have the Non-B visa with multiple Re-Entry which will be valid until 10th of February 2020, still the original visa, no extension of stay. My university, my workplace and the immigration center itself seem to give different answers of how I should proceed. I would like to stay in Bangkok for the change.
My questions would be if it is possible to get an extension of stay based on that I will start studying now but still hold the Non-B visa? If I would have to get out of the country to apply for the Non-ED visa, can I get the visa in addition to my current Non-B visa?
I hope you understand what I am looking for. My head is already fried from looking for answers online.