invalid ebuck vouchers issued by FNB

Bought ebuck vouchers for Sterkinekor. Tried to book with the vouchers just to be told invalid. Conveniently ebucks office closed. Checked on my ebuck statement and note the ebucks I used have been deducted. How can a bank take 'money' and not provide the goods. What do you call that again when someone takes money for goods or service but does not provide something in return!!?? I have logged a complaint but no hope of any speedy response.