Are you talking about the Turbotax fees ?
To contact TurboTax customer service/support use their contact website during business hours. If the problem concerns any type of refund for fees, use the key words billing issues and do Not use the word Refund or you will get a phone number for tax refunds.
Submit your question/problem during business hours and then use the option for Call (a phone number will be provided for Call) to speak directly with a TurboTax agent -
TurboTax support is open from 5am to 5pm Pacific time, Monday thru Friday
Note: The Call option will not be available when TurboTax Support is closed.
Use this website to contact TurboTax support during business hours - https://support.turbotax.intuit.com/contact/
Support can also be reached by messaging them on these pages https://www.facebook.com/turbotax/ and https://twitter.com/TeamTurboTax
When you requested your extension you were supposed to pay your estimated tax due. Did you enter the payment you made into your tax return? Go to Federal>Deductions and Credits>Estimates and Other Taxes Paid>Other Income Taxes
If you are asking about the Turbo Tax fees, you might have upgraded to a higher version or added a state return or some other service. Yes the fee you already paid should be accounted for and you just owe the difference now.
How to see your fees
Or you are not in the same account.