Where do I check about TurboTax refund for charging me to file my taxes when it was free to file

TurboTax is not free to file unless you have a very simple return.  If you were charged, then you did not have a return simple enough to be free.  There are no refunds for online TurboTax.  In the future, use one of the free services at https://www.irs.gov/filing/free-file-do-your-federal-taxes-for-free

TurboTax Free Edition is free as long as it is a simple return that files a 1040 with no additional schedules or upgrades. Please see Why am I being charged for TurboTax Free Edition? for more information.  

Since you have already paid, please feel free to contact Customer Support so they can assist you. If you inquire about a refund, you will want to use the keywords billing issues when you call so you get to the right person.

@Babyleigh41