I am not with Laminar Research; just a flight simmer from down under
You haven't indicated what your operating system is. Here is a link to the system requirements to run X-Plane and can be found at https://www.x-plane.com/kb/x-plane-11-system-requirements/ Serious flight simmers build a windows based system with components equal to or of higher specifications than the recommended specifications.
One issue you do need and not listed is good cooling as X-Plane is resource hungry and generates significant heat in the GPU and CPU. A purpose built PC allows you to upgrade components as and when affordable and as necessary.
At present you have raised your problem on the official X-Plane (Laminar Research) Q&A forum and not the steam version forum.
The steam version of X-Plane is a hybrid and not officially marketed by Laminar Research (LR). Any references by LR regarding Steam takes you to another site. LR only markets the official digital download or boxed version of X-Plane. There is an official licensed boxed version reseller in Europe.
My suggestion is contact the reseller of your version for the refund or raise your specific problem with the developer of the steam edition.
There are some steam users who look at this site and do help fellow steam users with problems. To get such help I suggest you attach the steam version of the official Log.txt file to your opening question so that it can be viewed to ascertain what the problem may be. This file is created every time you shut down or X-Plane crashes during a flight.
X-Plane should be loaded on to the desktop (windows based system) or a dedicated drive and not into any other file structure ie it needs to be in its own dedicated file structure. If not complications generally arise.
Personally, I have never supported the steam version.
Good luck in getting your refund if you can't resolve your problem by the other means suggested.