unhelpful service

I had sms confirmation that Heijman mechanic will come to check the heater box at my practice in Delft. I was busy working with my client and when I heard at the front door someone try to put the note in mail box. When i open the door I saw the machanic walked to his car , he walked back to me and just tell me to make new appointment. I was wonder if he come in front door and nobody opens the door why he didnt call me. I received sms information earlier then the company has my right nummer for sure and the machanic must have too. if he try to press the bell long enough why i dont hear it but I hear when he put the note in mail box. More worst than that when i try to inform customerservice the lady on the phone seem know only speak follow the policy pattern without try to listen what I try to inform. If you dont listen to what the client said how u would know the real problem and how you could improve your service in the future or you guy just dont care at all.