Bank cannot deny when they have given a letter with the due stamp and signature of the authorised person. In my opinion, it should hold as a valid proof. By the way is the capital gain amount now used to buy another property (u/s 54?)
case in assessee's favour
Income Tax Officer-1(1), Lucknow vs Smt. Aarti Kumaria, Lucknow on 14 March, 2018