Ransomware Attack! Had Windows Backup active but can't recover files

Hello Guys!
I'm new here, honestly never had problems with windows 10 until this time so i really need your help.

So i was attacked by ransomware yesterday, however i had Windows Backup funciotionality active. However i never need it so i never came across this problem.

So i formatted my computer, installed a clean OS everything is ok and now it's time to recover the backups.
I go to my storage NAS where i had the backups beeing made and i find out i have lots (almost 200) of folders with the name:

Backup Set 2017-05-20 (first one)
Backup Set 2017-05-27
...
Backup Set 2018-12-15 (the last one)

So i understand this are timestamps of the backups.
So i went to my last backup (15 December) and i saw i have lots of ZIP files on the inside.
I extracted everything.
However i noticed not all the files are present on this backup, so i went to older backups and i also see files there.

The biggest issue:
I had large outlook PST files, some of them with 20GB.
I can't find any of this PST files. What i do find is severall ZIP Files, and inside the ZIP files are the PST files but they aren't complete, they're with 200mb maximum and are in lots of ZIP files. the pst files have the same name so if i try to extract everything it says that it's going to overwrite the file.
Also, inside the ZIP files i have the same PST file separated. With 200Mb ... 30Mb... 20Mb ...

How can i put together my PST files?
Thank you!

I attach some pictures to explain better the situation

Have you tried using the Windows Restore features of Windows Backup?

mta3006 said:

Have you tried using the Windows Restore features of Windows Backup?

hello my friend. thank your for your reply.
I did but it said it didn't found any backup.

Or i'm doing it on the wrong option in control panel?

I am not familiar with using Windows Backup and Restore, other than making and restoring disk images. Check out this tutorial for details on how to use the restore function:

Restore Windows Backup in Windows 10

You might also direct a question to the author of the tutorial by putting the flag text "@Brink" in your post.
Hope this helps!

Steve C said:

In future consider using a better backup program like Macrium Reflect Free recommended my may on the forum

Hi Steve, thank you for the advice.
I'm going to download Macrium and try it.

Never had problems like this before.... and i trusted Windows... (this is probably the worst sentence ever written).

I am going to try the Guide mentioned before!
Thank you guys