If you don't use any software then do you get the blank forms and do them by hand? Did you use Turbo Tax online? Did you mail your return in or efile? If you efiled you might have upgraded to a higher version and didn't notice the fees if they were selected to be deducted from your refund. The refund only goes though the 3rd party bank when you have the fees deducted from a refund. You should call the SBTPG and see if they sent you someone else's refund.
Oh and you might check 1040 line 30 to see if you claimed an amount for the 1st or 2nd stimulus. The IRS has been adjusting returns for that if they already sent you the first 2 stimulus checks.
