Money returned by creditor

[pnut22]

I was checking on the data base and was surprised to see an entry returning money paid to a creditor. It says CANCELLED CHECK/TO PRINCIPAL and the amount. It's only about 33 dollars. I still owe this particular creditor about $800 so it isn't an overpayment. Any ideas on why they might give it back?

[CCB35]

they sent one of my creditors' check to the wrong address it was sent back with a note like this -however it said they would reissue it