worst online shopping experience ever

So first the whole point in my doing online shopping here was for a particular dress and a top. I bought a couple other things since I was paying 5.95 shipping anyways.
The dress originally had a size 14. I ordered it. 3 days later they processed my order and deleted the dress because they didn't end up having it. It sold out pretty quickly and I ordered a size 10. Then 2 days later they had a 12. So I ordered that.
Then They sent me the wrong item. It said specifically on the order form that it was a size 12 black dress lace. They sent me this really ugly kimono with fringes on it. It didn't even fit. If it were a cute kimono Id keep it. I liked all the other things. THe size 10 dress no where near fit me and I have other shirts and dresses that range from all sizes from that store. I have a size 10 dress that fits me perfectly. Plus the dress I ordered in a size 10 no where near fit the picture. Except the lace at the bottom. It didn't show or say there were ties on the neck.
The shipping was quickly but this is the worst experience ever. Im tempted to send everything back, but the shirts are really comefortable. I don't understand why the sizes range all over like that.
When I talked to customer service they claimed they were going to give me coupons and told me the code,but the coupon could not be used in the store. I think they should have given me store credit.