Accepted does not mean Approved. And the Turbo Tax refund date is just an estimated date of 21 days. Accepted only means the IRS verified some basic info on it so they know it's really from you. After it is Accepted the IRS processes it then approves it before they send the refund.
After Turbo Tax sends your return they are done with their part. Now it's up to the IRS to process and Approve it. It has nothing to do with Turbo Tax. The IRS doesn't update Turbo Tax with the status of your return. Turbo Tax just gives you an estimated date.
If the IRS says it's still processing at least you know they got it. All you can do is keep waiting.