How to install OS X Yosemite on MacBook (with empty hard drive) from Ubuntu or Windows?
You can possibly do an Internet Recovery with a new drive. Press Command + R on start up:

From Apple's website: 


  Newer Macs include the ability to start up directly from an Internet-based version OS X Recovery. Your Mac automatically uses this feature when the Recovery System on the startup drive isn't available. For example, if your startup drive encounters an issue, or if your startup drive has been replaced or erased. Internet Recovery lets you start your Mac directly from Apple's servers. Starting up from this system performs a quick test of your memory and hard drive to check for hardware issues.


If this doesn't work, taking it to the Apple store will be your best bet.