Sending buyers a return label. I sent wrong item

[rks_331]

I got my labels on the wrong packages and need to send return labels to the buyers so they can send the items back to me and then I can send it to the right buyer. I can't find out anywhere to send a return label

[simba6]

Have them file an item not as described case.    However, they will be refunded and would have to purchase the items again.   Also, you can't be sure that would both return the items.