CJ's Express Car Wash

On 11/30 I went to CJs car wash to get my final wash on the monthly service. I cancelled the service explaining that I was selling the car that day. On 12/19 my credit card was charged $31.93 even though I cancelled the service, sold the car and had not had the car washed again since I did not own it. I called to get a refund and they requested I return in person, which I did. I completed a form for a refund and still have not been refunded. The car was a Nissan Sentra plate, ***, 2017 Black Nissan Sentra