Someone tried to call me three times today. What should I do?

[Modem Butterfly]

My cell phone doesn't work very well in my office, so sometimes it will ring but I can't connect when I answer, and sometimes when I try to call out I can't get a signal. Today, I got three phone calls from the same number but no message. I called the number from my landline and it's the guy that mows my lawn, or at least his answering machine. I didn't leave a message. I'm pretty sure my partner forgot to mail the payment for this month, but I'm really annoyed the guy just tried to call three times and hung up. What do you all think I should do? Should I call him back and ask him what the hell's going on? Should I call him back and be polite? Should I send the bill and ignore the calls? Or should I just wait for him to grow up?