Refund cheque issued but not received

Dear All,

I just came to know my refund cheque not received as CPC issued the same on 28-08-2014 for AY 2011-12. Online status shows Refund cheque despatched by speed post but I have not received till date. 143(1) also confirms the refund due. Refund Reissue request shows there is no refund failure, this may be due to no refund being due or refund being delivered successfully. 26as also shows refund paid on 28-08-2014.

Please guide me..... Thanks