There are 2 places to see a list of lost customers, or canceled service sets
Sales KPI -
Under the company Tab > Sales KPI, you can populate a specific date range and use the Data Drilldown to search customers with a Lost status.
Canceled Services Report -
Found under the Reports > All Reports - The Canceled Services report has 3 tabs to show canceled service set information: Summary by Cancelation Reason, Summary by Default Team, and all Service Set Data. It can be filtered by Scope Group, Team, Zone, Satellite Offices, Frequency, and Customer Source. The Cancelation Reason tab also shows how long a customer received services before canceling.
After choosing a date range and any filtering you would like this report will populate multiple lists with the information of your canceled clientele