How can I cancel a customer order on my ecommerce platform?

[Unaas]

I am trying to cancel/delete an order from a customer. But I don't understand how to do it. (I've been using Shopify for 12 years now) 

What is return in profession? Why can't I cancel the order? 

Shopify is becoming more and more complicated to use in a way that is not flexible in any way - in addition to the fact that there is no way to reach customer service at Shopfiy anymore - I am very frustrated with the platform.