I understand your desire to get a callback. But before I hand you over, I'd like to offer help.
Aside from our phone/chat support, the Community, we also have trained support specialist that can answer QuickBooks-related questions. That said, may I know what are you trying to achieve? I'd appreciate any additional details that you can provide and I'd be happy to find a solution for it.
However, if you wish to get in touch with the previous agent, you can set them a request for callback. If you have a case number, you can give it to the next representative to to help trace your previous interaction.