Don't get too upset about losing customers. It used to bother me the first few years in business but now adays it's no skin off my back. It's just part of doing business - YOU CAN'T PLEASE THEM ALL.
The first thing to do when you get the call is find out why they want to cancel service. Many times, it's for a good reason; they lost their job....they are getting divorced.....moving away.....etc. That's all stuff you can't do anything about. Just thank them for service and move on. But if it's a service issue, then you need to try to assess whether it's something you are willing to resolve or not. Sometimes, people are just too damm picky. But ask and see what their issue is. As they speak, take some notes. If what they are saying is stupid picky stuff, don't worry about it. Let them be some other LCOs problem. But if they have legitimate complaints and you feel you can resolve them - try talking them into staying with you for another month or two while you try to resolve their concerns.
Still, losing customers is just part of this business. Get used to it. The trick is to always be growing more than you're shrinking. In the spring and summer we usually lose about 1-3 per month. But we're gaining 5-10 per month. So we always have a net gain. During the fall, we're still losing 1-3 per month (mostly just due to moving, lost jobs, etc.) and still gaining a good 2-5 per month. So again, growing. But during the winter (we mow all year here) we usually still lose 1-3 per month and typically only gain 1 or 2 per month. So all winter we usually have a net loss each month. But then come spring we're growing a lot again. It's just part of the business cycle.