How to re-install my macbook pro?
A 3-times beep normally means that something is wrong with your Random Access Memory (RAM).

You will need to replace it before you can use the mac. When you have access to another mac or iOS device you can download mactracker to see what kind of RAM memory your mac needs.

I think is 1067mHz or 1333mHz, but i'm not sure and don't know if there is a command to check the memory frequency.

After your RAM is fixed, you can reinstall os x. 
When you get the error message that the service is currently not availble, you can try another time are try to get a bootable device. I'm not sure if it is possible to make a bootable usb for mac on a windows.

If you can fix the problem by your own, you need to bring your mac to an authorised apple service provider. You can also go there to verify what kind of RAM you need, so maybe they can fix the os x problem when the reinstall your RAM if you don't want to do it yourself.