Rectification for Tax Credit Mismatch

For AY 2018-19, I had income from Interest on Securities and TDS deducted on that. I reported the interest income under Schedule OS and claimed the TDS as well. However, I wasn't granted TDS credit for the same due to Tax Credit Mismatch, as the deductor hadn't filed the TDS return. Now, the deductor has filed back-dated TDS return for the same.

I used the rectification option under e-file and selected the option "Only Reprocess the return" . But it has been rejected. How do i proceed now?

Thanks