Then just buy a bigger size??? Most shops stock from 8-20 (sometimes more, sometimes less). Depending on the material, sometimes you have to up or down the size, depending on the shop as well.
Crop tops are in at the moment, so of course they are going to be selling them; they want the money. Plus some people do look good in crop tops and it is, well, supposed to be summer. There are also some teens who need those kind of tiny clothes, who have not grown into their body yet. Not just teenagers - grown adults have the "10 year old who with no hips and no boobs" look. You haven't given us your height, but it seems like you're a size 8-12, which is extremely common.
With influx of "curves," there are plenty of shops that cater to busty women and women with back. Clothes that look good on a straight up and down person are not necessary going to look good on a curvy woman. Know your shape. Apple and Pear are very common.
I'm not really sure how many options you need...I'm not even sure how this could be a problem. New Look is quite forgiving in their sizes. H and M are a bit tiny - their size 10 looks like a 6 sometimes, but like I said previously, different sizes for different shops. Some might even say that some have vanity sizing.
If you're still having trouble, since you're on the internet now, why not just order online. There are so many sites for so many different styles, shapes and ages. Honestly I think you just had a bad (or another bad) shopping experience and felt the need to come online and moan about it. To each their own, I suppose...