Hi Marlin Imaging,
When you delete the customer in Method. it will automatically delete the customer in QuickBooks. We currently don't have a standard report in Method that will show you all of the customers that were deleted in Method or QuickBooks.
You can though create your own custom report in Method and I would start off by watching the following webinars as a starting point. I would first view the webinar titled Introduction to Designing Report: Level 1 here, Introduction to Designing Report: Level 2 here, and Tips and Tricks for Designing Reports here. After you watch the webinars, please don't hesitate to post a question here on the forum and the tech team will response promptly.
To also help you further, we have our other Method Webinars on Method CRM, customization of the product, and the other appications that we have here.
In regards to your comment about the fact that your telemarketers are deleting these customers, I would consider these contacted customers as Leads in Method rather then Customers if these are brand new potential customers that were not contacted yet. If they are truly leads, then they would not appear in QuickBooks unless the were converted to a customer in Method.
I hope that this helps.
Ronen