Ali Express hides from clients

Ali Express provide a fantastic selection of goods for on-line purchase & payment and offer buyer protection Once payment has been made and delivery does not take place, it is impossible to contact Ali Express There are no contact details on their website, they only offer info on frequently asked questions, but no other options My question, how does a ''reputable'' company like Ali Express operate and how can they make claims that cannot be disputed, seems they operate in a void that is unreachable