Make certain you send the tracking info as soon as you ship, or within 24 hours.
Keep all your receipt print outs.
And communicate at every turn about their parcel.
You can also go directly to your USPS and they will track for their pc. Generally, their in house systems are more up to date than our access online.
Because of the holiday I'd wait before you refund....maybe it will arrive tomorrow or Wednesday.
Good Luck.
