If I do not pay the national pension and mobile phone bills, what are the disadvantages in examining the documents for acquiring nationality?

When I was an international student in 2019, there was a time when I didn't pay about 200,000 won for my phone bill. Later I met and married my husband while living in Korea as an illegal immigrant. I am going to return to Vietnam and apply for a marriage visa. Would it be difficult to apply for a marriage visa because of the phone bill that was not paid in 2019? I want to pay my unpaid bill even now, what should I do?