USELESS Vouchers

I really do not like the fact that you get royalties and vouchers to use on your next visit, but then are told when you want to use the voucher that it is not showing on the tellers pc in the restaurant. When I show the waiter my app and inform her I have available vouchers left, they couldn't help me. PLEASE LET ME KNOW WHY YOU GIVE VOUCHERS I CANNOT USE?

Membership number: ***63 2694