Wind prepaid number how long active?

[austria]

Hello, I have a Wind prepaid card, I have to top it up every 2 months, each time at 12.- never i make outgoing calls, I only use the number for incoming calls. Now I have some questions:

1.) Is it possible to have the accumulated credit paid out?

2.) If I don't top up every 2 months, how long will the phone number stay active for incoming calls?

3.) Is there a wind page where I can find out more about the conditions and the period of validity of a prepaid number?

Thanks for the help!