First off to be clear the job was not $3800 in total and to start, I was asked as a favor to come and look at the duct work at the customer house because he was redoing his roof and was worried some of the work was damaged and also wanted a duct run to the addition for extra cooling. After I did my inspection, the custom had also wanted the air handler moved from the attic to the garage for easier access in the future. A quote was given far under what it would normally cost because the customer was also a friend at the time. I started the job and had to unfortunately leave and come back the next day due to unforeseeable complications on the job and it is getting really late for the customer.(I was willing to stay and finish the job but i left because it was late and the customer asked me too), I told him he would not have ac, but he said it was fine because it was cold outside. I then told him OK I will be back the next morning which was a Saturday, the customer said OK, and I left. The next morning the customer called me one time at 7:35 am the next day and because I have a newborn and it was the weekend my phone was on silent, I realized he called and texted back asking if everything was OK and letting him know I was on my way. He replied he was upset the job wasn't done and he didn't want me to come yet. I attempted to try and call him he then texted back he is busy but to not come. I said OK and was then contacted by a mutual friend and told the customer was upset because I didn't answer my phone when he called. He later calmed down and asked me to continue the job, which was now in the afternoon, so I lost almost a whole day's time to work on the job causing it to "drag out" as it was put. The job had to be finished on Sunday due to the fact that I wasn't able to finish the job on Saturday since the customer made me start late. While I was doing the air handler job, I found mold the ducts and recommended we replace then but the customer only wanted the 4 ducts that were crushed from the roof job. I replaced the ducts and because I had a new helper there was a spot on one of the ducts that did not get tape or mastic because I forgot to go back and check my helpers work which I do normally do but given all the issues and time I had spent on this job I forgot which was a mistake and honestly i am only human. On Sunday the next weekend I was texted by the customer saying he was upset cause the work was not done correctly I asked him what he meant he then sent me a picture of the one duct that was leaking. HOWEVER, before I could respond that I would fix it after church he texted again not to worry about it, he would take care of it and that was the end of the conversation. Had the customer allowed me to I would have taken care of the issue and I would have made sure everything was fine before leaving at no extra charge obviously. I have done work for both their house and their business, and they never had an issue before. I was honestly surprised given the fact that the customer is a contractor as well that he did not give me a chance to make things right.