I bought something one Sunday, checked on it the next weekend, the seller said he was shipping it today. Checked the next weekend, the seller said he was on the way to the post office. Checked on it the next weekend, the seller said it was sent during the week, never arrived. I had to assume the Post Office lost it (not the first usps lost one), and let it go.
If your seller didn't confirm it was shipped, check with your seller. If he did confirm it, its in usps hands, and you can't do anything without tracking. And even with tracking, they still won't do anything. Sorry, I'm a little cynical with the post office.
Standard 10 Gallon (20 x12x12).
Low tech, Sand substrate.
Eheim 2211, and Aqueon Quietflow 10.
Finnex Stingray LED, 20" above substrate
2 Anubias Nana Petite, Christmas moss.
4 Halequin Rasborahs, 5 RCS.