All contacts lost after turning on icloud IOS 5.1.1

Today I turn on icloud on my iphone 4 using ios 5.1.1 to sync my contacts, once it done, all my contacts disappeared from my address book.

I have done everything I can and search on the internet but no way I can get the contacts back. I already tried turning off icloud and choose Keep on my Iphone option, tried turning on icloud again but also no luck, when I log into www.icloud.com with my account, my address book is also empty.

What must I do now? Why on earth Apple allow a software to wipe all the data (in my case - my contacts) from the user's phone without providing a convenience way to backup in a user friendly manner?