Did you use OneDrive to sync your files on the laptop that was lost?
If so, there are two options available.
1
Open the Settings App.
Go to Accounts - Your Info.
ON that settings window, you should see either the option to 'Switch to a Local account' or the option to 'Stop automatically logging into apps with this account'.
Select whichever of those two options exist, that will switch the user account to a local account.
Wait a couple of seconds, then click the option to switch to a Microsoft account login and add the details of the Microsoft account you used on the lost laptop.
Then ensure you log into OneDrive on the taskbar using that same Microsoft account.
Your files and settings should then sync down to the new laptop.
2
Otherwise, you can create a new user account on the new laptop, then sign into that account with the old Microsoft account details, then delete the new account the shop created on the laptop.
Open the Settings App
Go to Accounts - Other Users
Click 'Add Account'.
Follow the prompts to create a new account
Close the settings app
Log out of that user account
Log into your new account
Click the Start Button, type netplwiz and hit Enter
In the resulting dialog, select the old account and click 'Remove'
That's It, your new Account will replace the old account.