Ford Credit Paid car off 100%, and they took 300 after that. Nationwide

 I decided to pay my car off 978.27 dollars, because their online payment site is constantly giving bad gateway errors. I called the day before the payment was due and paid the car off in full using their automated phone system. The next day, they pulled 300 dollars from my account. When I called they said I must be on auto pay, I replied. Nope never turned that on. Please put the money back. They admitted mistake, and said a check was going out. Couldn't just replace it. Why not? U took it when my balance was zero. I asked where it was being sent because I had moved and couldn't get past bad gateway to change address. I was told it would be 30 days. That was 35 days ago. I would like the interest on the stolen funds, as well as any interest they made on the money. Why should they profit on their mistake.