Voucher system conveniently offline

Lately whenever I'm I've been going to Spur, today being one occasion recently the voucher systems is always offline, this is the 2nd time now experiencing this, the store is unable to process any vouchers and therefore I have to pay a higher bill amount. This happens specifically on Mondays when the burger special is running. So after paying the full bill I'm sitting with 1 voucher that will expire soon (Total of 2 vouchers on my app) . What is the point of having a loyalty program you cannot use? Both occasions at California Spur, Westgate Mall