Amplify | Bundles & Upsell

I uninstalled this application because I was changing the theme for my store. I was going to reinstall it after the switch, but I will never work with this developer again. Aside from the monthly fee, there was an unspecified charge on my bill after the uninstallation. I asked the developer to explain and specify the reason for the charge; they claimed I breached the tier by generating sales with their application. However, their application was barely functional for my site. I asked them to specifically explain the sales generated through their application, but they failed to do so. They are still keeping the money, and their customer service is extremely poor. I am very upset with this developer, and I do not recommend their application to anybody.