The self-employed who isn't happy with his boss

I recently got a card in the mail from our piano tuner reminding us that it has almost been a year since our piano was last tuned and giving the (new) phone number of the tuner so it would be a simple matter to call for an appointment. It was therefore with some surprise that when I called, the initial response was, "I'm on my break. Can I call you back this evening?" I could almost understand "I'm in the middle of an important meeting" or "I'm just about to finish this job. Let me call you right back." Or even have his answering machine take my call and promise a return call. But the response "I'm on my break" just floors me. I got the message, intended or not, that he has all the business he wants and could I just stop bothering him> Especially during his break!