Getting diferent versions of one game

no, the only thing that will happen is that the extra content was installed or added to your account, that is, you will be given the extra elements of the higher versions that you have

Unfortunately no, a refund would not be issued under the circumstance you mentioned.

To be able to get a refund you would need to do it in the first 14 days after purchase, and have not played more than 2 hours.

D. All of the above (see update preview forums...the answer is in your question, your versions are incompatible since they are diferent UI's)

Theres' two version of The Witcher 3 game on the store. The standard version (dlcs apart) and the Ultimate (all dlcs included). Both are
"diferent" games, according to the microsoft store. I don't know why things work this way, but the version in this quest is the basic version. As you know, the standard version is already in the game pass, so you can try it out at any time.
Alternatively, you can report this issue to Microsoft Support and request a position. Here's the link:

https://support.microsoft.com/pt-br/contactus/