Policy
If the box comes back
Wrong band for the dog on the scale, or a vet said switch — returns run entirely on the retail partner's policy for the listing you bought.
Start from your orders page with the partner; labels, refunds and timelines are theirs from first click to closed case.
One field note: weigh the dog before ordering, not after opening. Topicals in opened boxes return poorly everywhere, and the sizing guide exists so the first box is the right one.
If a listing steered you wrong, tell the guide anyway — the card that misled you gets re-read and rewritten.