Actually 'windows' has been playing catch up to linux for decades. All the major servers around the world run linux as it's vastly superior system.
But............................... that doesn't answer your problem. Phone support for the best advice, as only they can reimburse you and reset everything, as long as it doesn't fall outside policy and terms.
Hi @amolk, hopefully you've already been in touch with support about this, but if you haven't, please be aware that you can't change operating systems once you've purchase a hosting plan. In order to get moved over to the OS you're wanting to use, you'll need to cancel the old plan & then purchase a new one. Our live support will help you with this process. Please call at your earliest convenience.