What they are stating is fair. As far as in Europe (and maybe in other countries as well), it's the store who needs to provide warranty cases with the consumer and not the company of the product. So if you claim warranty, you need to contact your seller rather than directly Wheeltop.
This is different. they are saying that the only way to buy their products is via their website.
what you are saying is what LTWOO is doing for eg, which is, in case of warranty issues, you contact your reseller, and the reseller liaises with LTWOO. I know that 1st hand, given i'm now on my 3rd dead ER9 RD, and every time i go through the reseller, which is torture.