I'd be surprised if those addresses are routed to the same local offices. I would have expected the card for the TS28 address to have been sent here:
Wingate Delivery Office
Front St E,
Wingate,
County Durham
TS28 5AG
whereas the card for TS26 would probably have been routed via
Hartlepool Delivery Office
Clark St,
Hartlepool,
Cleveland
TS24 7AA
The Royal Mail website seems more designed for claiming compensation than for actually forwarding information to local managers, but you might want to take a look at it:
http://www.royalmail....00144&mediaId=3100065
You might find it easier to write to the addresses above.
Chris