Wimpy No Rewards System

I have come to the conclusion that the Wimpy rewards system is a marketing ****. I can just about never get a receipt that I can scan. The excuses are system down, should have asked for a different kind of invoice etc. We have not been able to scan and add about 8 transactions. The Wimpy at Bloemfontein N1 has now for the second time not been able to give us a invoice/slip that we can scan. Last year July they had a problem with the system and now still have one. How can Wimpy advertise something and then not fulfill their advertising