Complain

Three weeks ago I have purchased a sneaker online and everything was approved, usually they communicate with me till I receive my orders but this time they did not, not only that but I also did not get my sneakers. Now they are no sizes on the same sneakers when I try to purchase again. If the was a problem I believe they should have let me know. I even got an order number, everything and I waited and waited to be contacted but nothing.