Unfortunately, you are going to have to wait until the IRS has caught up with their backlog and is able to take your call, OR you can dispute their decision by mail.
TurboTax has no ability to resolve this issue with the IRS. The IRS processed your return and think you made an error that changed your taxes.
As @JohnW152 states - "You’ll need to follow the directions in the letter you received to dispute the adjustment. Make sure you follow the instructions exactly, and be aware of whatever time-frame is noted for contesting the decision"
