Rude Customers After Tech Support Help

I got a call from an older lady who stated that after installing our software, her mouse would not work. After further questioning, I learned that she got a message when booting the system that a device was not found. I had her power off the PC, disconnect, and then reconnect the mouse. After rebooting, the mouse functioned fine. But instead of thanking me, she asked me sourly, "Why did your software unplug my mouse?"

I attempted to explain to the lady that that was not possible and that all it was was a loose connection. It wasn't good enough for her. She put her husband on, who asked, "Why did your software decide my computer didn't need a mouse?"

Again, trying to explain the loose connection was of little use, and he wanted another number to call to return the software.