I bought one of these cases on Amazon – Custype - 手机壳定制 Custom phone case Review

I bought one of these cases on Amazon and was looking for a way to buy the additional replaceable covers. You can buy either just the cover for the iPhone 7 Plus for $60, or you can get a cover and a case for $20. I don't know why getting just the cover is so much more expensive, especially considering if you get the iPhone 7, 6, or 6 Plus cover it's only $15. I downloaded this app thinking I'd find a simpler solution, but everything is in Chinese and even when I use a translating app to figure out what everything means I can't sign up for anything. I even went to the Custype website but I don't see a customize option let alone an option to only buy a customized cover.
Review by I want my tabs on Custype - 手机壳定制 Custom phone case.