Refund chq got undelivered. how to get it back?

I have filed Income Tax Return online and I saw the Status of Tax Return online as "No such Address - Refund voucher cancelled. The instrument returned undelivered by the speed post as the address provided by the assessee is not complete/ non existent."

There is no change in Address and the Address mentioned while filing address is also correct.

PLSS help me out! How to get the refund back?