"Loig Pro" The application could not be downloaded

Hello Apple, this is my first post.

I've just format my mac and I have Snow Leopard v10.6.8

I go to the App Store to download Logic Pro 9 that I bought before and after download says this message:

The application could not be downloaded

The server gave an error during download: 503 service unavailable

What can I do?

Thank you!