About Time Pressure Washing

I bought a Half Off deal voucher for 600 sf pressure washing. Derek, the owner, sent an email on Thursday stating work would be done on Friday afternoon. Friday...no show, no phone call. I called Derek around 6 pm and was told it would be done on Saturday, no apology.  Saturday was also a no show, no call. I called him Sunday morning, letting him know no one had showed and asked when it would be done. He couldn't say when...just whenever they could get to it, but said he would call me back in 5 minutes and let me know when it would be. He never called back. I feel this business is undependable. And despite the fact that I was always polite with Derek even though I was disappointed that he kept dropping the ball, each time I spoke with him he acted  unprofessional in that he was curt and sounded irratated with any questions I asked of him;  I got the impression that he didn't like to be bothered.  . 
When they did show up, Eric did the work and we were pleased with him and his work, including his pleasant and professional demeanor.