Another ugly case of monopoly

Nets charging $5 not refundable for a new card that has an expiry date. First, why must there be an expiry date if the card is in good condition? Many people bought more than one card, some kept as spares and hardly used. Secondly, is the $5 justified?

Why allow only one organisation to monopolise the sale of such a card to the public when usage is almost unavoidable or near compulsory to some?