QuickBooks overcharged my monthly subscription payment who can i contact to solve this?

It is best to check your billing history first to see exactly what triggered the extra cost and to identify the specific charge on your account. 

Then, if you notice anything suspicious after checking your history, contact our live support team for a review of your account and to check any discrepancies.

To reach them, go to the (?) Help icon > Contact Us > enter a brief description of your concern and click Continue > Choose how you would like to connect with them.

Let me know if you need anything else. I'm here to help.