I’m deeply indebted you

You mean 교환하다, 교환하다 is exchange you can say for instance: 메리가 지수와 언어를 교환하고 있는데, 메리는 지수에게 영어를 가르치고 지수는 메리에게 한국어를 가르친다. Mary and Jisoo are exchanging languages, Mary teaches Jisoo English while Jisoo teaches Mary Korean. It can be used with situations when you are giving something in return of receiving something back. Or when you're swapping one thing with another thing like: 작은 치수의 바지를 큰 치수의 바지로 교환했다. I exchanged the big sized trousers for a small one. 바꾸다 is a general verb means change You can say -원피스를 주로 입는 메리가 출근하면 정장으로 바꾼다. Mary who usually dresses in dresses, changes to a formal attire when she comes to work. -밤이 오면 해가 달로 바뀐다. The sun changes into moon when it's night. It can also be used in cases like the second example of 'exchange' when you are changing something with another thing. 핸드폰을 켜는 비밀번호를 얼굴 인식으로 바꿨다. I changed the mobile password locker with a face recognition one.