Wrong tan entered

A taxpayer entered the wrong TAN, preventing TDS from being applied correctly, leading to a demand notice. They are unable to file a revised return as the assessment is complete. The issue arose because the buyer's CA obtained a TAN and applied for LDC simultaneously, while the buyer's CA also applied for a separate TAN and paid TDS using it. The LDC is linked to the previous TAN, resulting in a short deduction notice. The user is seeking advice on how to rectify this situation.