I ship via USPS priority mail and have tracking numbers available. If the item is listed as delivered, but you did not receive it, that is between you and the USPS. I ship very promptly and you will receive your decal quickly.
Refunds are available. Items must be returned in "sellable" condition. So, if you bought it and received it and changed your mind, that is ok. Anything used, or partially used is not returnable. Shipping is not refunded under any conditions.
To apply the decals, follow the instructions on the packaging.