Smart shopper - not such a smart idea afterall

Received a smart shopper voucher for R30 discount when buying R300 rands or more.. so I went on the 28th of April and wanted to redeem this voucher after spending more than R300 , the voucher did not work and I was told the system is offline, I went back the next day and it still did not work. I stood there for 10 minutes while the supervisor struggled and could also not get it to work. The customers behind me was impatient , and this was also a waste of my time. This voucher also expired on the 3d May. I do not understand how pick n pay can release vouchers and are not able to provide the discount at the end of the day.