A friend who lent 500,000 won but doesn’t pay back

(1)I lent 500,000 won to my friend, and my friend’s mom gave me 1
(2)He gave me 2 million won
(3)In early May last year, my friend suddenly told me that he had an urgent matter
(4)I lent him 500,000 won
(5)You said you’d pay me back within May when you borrow it
(6)He didn’t pay me back even after June and July, so I asked him when he would give it to me
(7)Why did you get mad at me
(8)In September, he got really angry and cursed at me for asking if I was a loan shark
(9)I thought I donated 500,000 won and stopped contacting my friend
(10)But yesterday, I met my friend’s mom by chance in the neighborhood
(11)I’ve been close since middle school, so I go home several times and my parents know
(12)I was going to let it pass, but I thought it wasn’t polite to an adult, so I said hello
(13)My aunt asked me why I haven’t been home lately because it’s been a while
(14)So I told you honestly
(15)”I lent 500,000 won to my friend last year, but I couldn’t get it. I lost contact with her
(16)I was surprised and asked if that happened
(17)He said he’s going to return the money because he doesn’t have any cash
(18)They told me to wait at a nearby cafe to get it out of the machine
(19)Honestly, I wanted to get my money back now, so I waited at least now
(20)But the lady gave me 1 million won
(21)I lent 500,000 won to my friend
(22)I didn’t get paid for it for nearly a year
(23)I’m sorry, so I added more. I hope you warm up now
(24)He said it was everything
(25)I said it was okay and refused several times to get 500,000 won, but my wife said she would feel comfortable if she asked me to get it
(26)I got 1 million won to thank you
(27)But when I got a call from an unknown number this morning, he called me crazy and swore at me
(28)I only need 500,000 won. Why do I get 1 million won from my mom
(29)”Isn’t this a thief?” I cursed a lot
(30)And he asked me to return the 500,000 won
(31)He told me to transfer money or give it to him. So I asked him if he should apologize first
(32)He asked me what I was talking about and asked me to give him back the money, so I hung up on him to think about it
(33)I was worried about getting 500,000 won more, but they gave me back
(34)Is it right
(35)But my friend came out so brazenly that he honestly gave it back
(36)I don’t like it
(37)I can’t find the answer. What should I do
(38)You have to give it back vs. You don’t have to give it back