Query ? unable to credit refund amount due to wrong a/c no ?

" UNABLE TO CREDIT REFUND AMOUNT DUE TO WRONG  BANK A/C NO "

For the a.y 2014-15, As per NSDL Refund Status shows ( of my client ) as 
" Unable to credit refund as the account number provided by you is incorrect " & that's why after log in ,  i choose " Refund Re-issue Request option " with all correct details ( bank a/c no, cpc ref no, refund seq no ) & i am really surprised bcoz when i submit all the details , an error message shows that 
" There is no refund failure this may be due to no refund being due or refund being delivered successfully " 

Please tell me 1) what's the actual meaning of the above message ?

2)Tell me the procedure to claim the refund amount as early as possible  .

Thanks.