If it comes back
The return goes where the payment went.
Where a return starts
Whoever took the payment handles the refund, and that is the listing you bought from. Open the order in your account there, choose the return option on it, and follow the steps through. The window, the condition rules and the money all sit on that side.
We have no order records, no return labels and no way to move money, so a message to the workshop about a refund only adds a day to it.
When it is a fault in the sewing
A seam that opened, a zip that jammed on the second use, a snap that pulled through the cloth: start the return on the order page first, because that is the fastest way to get you a working piece. Then write to us with a photograph.
Faults tell us something a review never does. A zip that fails in the same place on two pieces is a pattern problem, not bad luck, and it gets changed at the table.
When it simply does not fit
This happens most with covers for infant shells, because shells differ more than the photographs suggest. Send it back from the order page, and if you tell us the make of the seat, we can usually say which piece in the range would have sat better.