Return To Sender

I gave a letter to the postman, he put it in his sack

But the very next morning, he brought my letter back

One of my recent applications came back to me today marked return to sender.  They hadn’t ticked which box why, so I checked the address I’d sent to.  I’d got the address from the current DSC guide, and I check the Charity Commission website, which had the same one listed.  The address appeared to be a legal firm, so I tried searching for them online, and found out they’d merged with another firm and moved.