I understand your desire to get a callback. But before I hand you over, I'd like to offer help. Here in the Community, we have trained support specialist that can answer QuickBooks-related questions.
May I know your concern? I'd appreciate any additional details that you can provide so I can help you out.
However, if you wish to get in touch with the previous agent, you can set them a request for callback. It would be best if you have a case number handy for a more convenient tracing of your previous interaction.