Here’s what consumers have asked with answers from EZcosplay staff and previous consumers.
I never tried to contact customer service, but after I received my package, they reached out to me to make sure I was satisfied. I had 0 problems shopping with them, shipping, quality, size, or otherwise. Just read the shipping descriptions (they caution you that it can take a while) and the size charts (maybe go up a size), and you'll be fine.
Yes, it's normal. It just goes through as default XS. Not to worry, they will make it custom. Check out their FAQ page if you're still worried.
I'm not sure which country's sizing is used in the size chart, but I normally wear a US XL, and that was what I ordered, even though the measurements in the chart were bigger than should have fit. The dress fits like a dream, so maybe order your normal size (US). If you use the size chart, you might want to consider going up a size.