Refund processed through cheque and not credited to bank account directly

I have a client and whose refund for the year 2014-15 is not credited to bank account directly but is processed by issuing cheque from the Income Tax Department. I checked the ITR there is no option to tick whether the refund to be processed through cheque or direct credit. Can anyone tell me why is Income Tax Department issuing cheque instead of crediting directly to the client account even though all details for bank account for direct credit has been provided in the Income Tax return. Thank You.