from D-2 to D-10

Hello everyone, I’m trying to contact immigration but they are not answering my calls, so I’m hoping someone here might have some information. I graduated from my Korean university last week and my original plan was to change my D-2 visa to a D-10 visa in order to start looking for a job and eventually get a sponsored work visa. However, my D-2 visa expires on March 30, and I haven’t been able to get an appointment at immigration before that date. Another complication is that I will be going back to my home country for about three weeks for vacation. Because of that, I assume that when I return to Korea I will enter as a tourist. My question is: Can I apply for a D-10 visa after returning to Korea as a tourist? Also, since I graduated from a Korean university, I believe I don’t need to go through the points system for the D-10 visa. Is that correct? If anyone has experienced a similar situation or has information about this, I would really appreciate your help. Thank you!