Tivusat is not a pay television, no subscription required.
It is intended to broadcast italian DTT on satellite for all those people having poor terrestrial reception.
So your card does not need renewals as a subscription. But they often change cards for security reason. When they do that, they send new card to all registered users and deactivate the old one. So you must be able to get the new card, possibly sent to the user address to which the card was assigned.
I suggest you to contact the user and ask him if he received a new card or possibly any email or letter from Tivusat.