To Dry or not to dry...

I always use this laundromat and I never had a problem until Monday. The place locked up early with my clothes still drying. When I went to pick them up the next day, they were taken out of the dryer and still damp! I called to inform the owner of the incident and he stated that he will give me a free wash and dry to make up for it. The son soon after called me back to tell me that he was "irrate" with me and continued to tell me his version of what happened which was wrong because I have receipts with time stamps. He told me that he was not there for my convenience and he will do what he likes with his business. That I was lying and to not come back becuase he refuses to let me have a free wash and dry. He continued to become more angry and yelled at me for about 5 minutes insulting me in front of an office of paralegals and lawyers. He would not let me respond or want to hear what I had to say. There are no store hours posted and last dry doesnt start until 8pm. I was back at 7:45pm. Hint: Do not put up signs with times of last wash and dry if you will not adhere to them. I attempted to call the owner back however he repeatedly picked up and hung up without answering the call. The son was was rude, customer service is nill, very offensive, I did not appreciate it. Based on my experience this business is very unprofessional.