Can turbotax be incorrect? turbotax says i didn't use them to file last year, but i did. What do I need to do to?

Many people have multiple TT accounts and forget how to access them.  Log out of the account you are in now.

 

Account Recovery

https://ttlc.intuit.com/questions/1901535-forgot-your-turbotax-online-user-id-or-password

 

 

https://ttlc.intuit.com/questions/1901486-how-many-turbotax-accounts-do-i-have

 

Or did you use the desktop version of TurboTax?  If so, the files are on your own hard drive or any backup device you used like a flash drive.