A Microsoft support person remoted into your computer and deleted files?
This sounds like one of those fake Microsoft support scams in which a person pretends to be Microsoft and intentionally deletes data and asks for credit card info.
Additionally data like that should be placed onto a server with tape backups or some other backup means to avoid total data loss. If you never ran any backups or saved data to an external device you may never see it again!
Your best bet for this system right now to try to get any data back from it is to shut it down and stop using it as for any further use after the deletion of files increases the likelihood that the sectors on the drive would be reused to store new data. You may be looking at a partial to total data loss of your important data because of this fact.
There are tools out there you can use yourself to try to undelete files, but given the importance of these files you might want to hire this out to a local computer shop to go in carefully and try to retrieve files that have been deleted. The best method is to use a Live Linux OS which will not write any data to the drive and try to recover files for you to another drive such as a USB stick as for with Windows running, the longer it runs the more likely it will overwrite the sectors were the important data resided since Windows has the sectors flagged as free space to be written to and data there with the important files overwritten.
