I had a contract with someone to sell them my my father's car and now I have to renig on the situation because my father said no

I have tried giving the person back the money that they gave me towards the car note at a prorated amount because he has been operating the vehichle for the past 14 days putting mileage on the car and everything. And I am sure that any rental service would do the same. I have contacted his insurance company and they have agreeed to give him his money back. please help ASAP!!!!Yes, it was not my car to sell in the first place is what i am trying to explain to the person. I was trying to set up someone to take over the monthly payments of 215. And when i had someone in mind that was willing and able i informed my father and he said no. that it did not sound like a good idea and that the contra