Pre-validate bank account

Dear Sir/Madam,

Does anyone have nay idea how long does it take to get the bank account pre-validated from the Income Tax efiling portal?

I have account with Union Bank and I submitted my request yesterday, it still shows pending.

Contacting union bank cust care says contact branch, when I contact branch they say write to ebanking and in the end no one is responding.

also what should be the next step if the pre-validation fails?

There's no clarity on this topic neighter  from bank nor from income tax department!

Thanks and regards