Worst Online Service

I have had the worst experience more than 3 times on my online purchases. The one took almost a month to get to me and they do not care at all. The second one i paid and i got an email telling me that the shoe was sold out. The third one, i still got an email saying that the shoe was sold out. But no refund yet. My question is WHY IS THE SHOE. AVAILABLE ONLINE FOR PURCHASE if they can't get it. Then there is no contact number for these people, you send lots of emails and you don't get a reply.