CarMax

I recently purchase a car from CarMax on Sahara on 2/24. Monday 2/26, the check engine light came on. I took the car in to get serviced 2/27, I was told it would be be fixed by the weekend. I was called Friday 3/2 and was told the car parts took longer than expected to come in, so it wouldn't be ready until that Monday. 3/5 I was called and was told that another issue appeared to be wrong with the car, and because I was under the 5 day return policy, seeing that the policy was put on "hold" while the car was being serviced, I had the option of returning the car. I returned the car Tuesday 3/6. The return agreement stated I would have my down payment returned and that the car loan would be returned to the loan company and that the loan would not appear on my credit report. 3/9, I went to a different dealership and I was not able to get a new car because there was an open auto loan account from the auto loan company through CarMax, though CarMax stated it would not be... I called CarMax and the loan company American Credit Acceptance (ACA) and was constantly going around in circles with them, calling back and forth, being put on hold for hours, and the loan still appears on my credit. I tried to get a payoff letter saying that the loan was returned and I owe a $0 balance, but I was not able to receive one for some unknown reason. I returned the car 3/6, it is now 3/15 and I have been without a car since I returned the car to CarMax. I have Sickle Cell Disease and Junior Rheumatoid Arthritis, I have doctor appointments to go to, I have to go to the pharmacy to pick up medications, etc... I have been using Lyft/Uber for transportation seeing that I am not able to walk long distances to ride the bus. I am a long-term substitute, I work with pre-k autistic children and I'm a college student. I desperately need a car to get to and from work and to run my errands. CarMax has been no help whatsoever! And they created a giant mess for me! I am highly displeased and irritated.