You can reinstall your VPS OS anytime in VPS control panel.
Login details was received by email when VPS server was activated.
To reinstall VPS OS:
1) Login to VPS control panel
2) Select your VPS server from the list by pressing "Manage" button on the server line
3) Press "Reinstall" button on the bottom of the server details page
4) Choose OS from the list
5) Press reinstallation button
6) Your OS will be reinstalled after a few minutes
Warning! OS reinstallation will permanently delete all data in your VPS server and clean empty OS will be installed, so you should make backups before reinstalling VPS OS.