WHY SHOULD A GIFT CARD EXPIRE? AND NO NOTIFICATION GIVEN ?

GIFT CARD EXPIRY REIMBUR*****T PLEA. Why should gift card have a expiry date. Sometime one forgets about the gift card or never require to use it at the time, misplaces it and the monies are at the end lost. Companies gain this money without merchandise leaving the store. I have lost some money on a gift card, where the shop has gained money. would think this is ***** to put it mildly. I have requested for the money to be reimbursed but no reply on several accounts.