<prompt> Human: I just had a conversation with my grandpa, and I feel extremely upset. In October of 2012 I was having car troubles, so rather than sink more money into the vehicle I already had, my grandparents decided to help me buy a new car. My grandpa found a used 2012 Hyundai Sonata near by and I liked it a lot. The deal was that he would take the cost of the car out in addition to a loan he already had out from his bank, he wrote a check, and it was my responsibility to repay him. Thats more than fair. I was informed by both of my grandparents that I was NOT responsible for the interest on the loan. They would pay it because they had the initial loan and since I was working on paying off all debt I have, they didnt want me to worry about it. As of today, my remaining balance for my car is 4,163.43 which I intended to pay off before I move in with my boyfriend in four months with a combination of my savings, my regular monthly payment, and my tax return. I am not behind on the loan by any means. Today my grandpa told me he decided to charge me interest on the loan in the amount of 2000 and I now owe him an extra 200 per month. There was no conversation about it. I believe he is doing this because of a recent disagreement we had about our relationship. Hes very abrasive and intimidating which makes it difficult for us to communicate. Am I stuck paying this interest? Is there anything I can do? This is very upsetting for me because I have worked so hard on paying off all of my debt and I feel like hes doing it out of spite. Please help. EDIT- Thank you for all of your replies. For a little more information, the title of the car is in my name. The loan is in my grandpas name. We have a book where we keep record of all my payments which I took to get copies of. It shows my initial balance and my current balance with all of the dates of payment. As far as the dealership is concerned, the car is paid for. He took a private loan from his bank. UPDATEFirst, let me say,I have read every comment and I sincerely appreciate all of the advice youve given me. After a lot of thought and consideration, Ive decided that my best course of action is to pay the interest on the loan, but I will do so on my own terms. I am not going to increase my monthly payment as he requested, and he is going to have to show me a breakdown of the interest because it is combined with his personal loan and the loan was set for 60 months, which is twice as long as the duration of time it will take for me to pay off the car. You guys are awesome!  <response>: Since you didnt sign any loan documents from what it sounds like you could likely stop paying, not pay the 2k, and give the car back. This is assuming he title of the car is in his name. If it is in your name you could likely just stop paying all together. If you dont have a contract with him and you havent signed a new one you dont retroactively owe him 2k just because he says so, though you may have to give the car back. 