Smart Shopper vouchers

The ink on Smart Shopper voucher slips wear off before you can use them (for future dated vouchers). Same goes for till slip vouchers on next shop. Keeping the slips is a pain firstly, and even more so when the cashier informs you she can't read it because the ink has disappeared! Only ranting seems to get results and even then it's such a long procedure to correct its not worth it!