>>4089i'm not sure what options you have available in your country, but here i can go to any newsstand and buy a sim card for like 3€
the card is "valid" for 90 days without being topped up, but topping it up with lowest amount (3€) resets the timer, paying more probably increases the validity more, but even if the card "expires" the only thing that happens is you can't make outgoing calls, incoming still work, and i think there's another 90 days of you not topping up the account where the number will expire