What's wrong with entering Tmall to buy goods and not being able to communicate with the store?

Some products in Tmall Supermarket are not supported to be sold to remote towns and villages (because express delivery is not provided). The Tmall page reminds that if you choose, you can't place an order or communicate with the store. And if you click on the product you want to buy in Tmall and enter a store, you can click on the customer service and Wangwang communication store.