I'm stumped as well. The usual solution is delete the 1099-INT and start over. But, in your case there's a simple solution. Since you're not eligible for the USSB interest exclusion, just answer no when asked if you used the bonds for education, and avoid that part of the interview.
Even when TT does it right, it's going to generate a form 8815 that says you don't qualify. That form will not be sent to the IRS as part of your tx return.
Since, you're not getting the interest exclusion, your entire contribution to the 529 plan should have been identified as "Basis". None of it should have been called 'earnings", since the earnings portion (interest) is being taxed. Be sure the contribution was identified that way, so you don't risk being taxed twice if for some reason the 529 plan is not all used for education in the future.
