Discovery Vitalitydrive keeping client's cashback

Discovery Insure lure clients in with the rewards program. You'll receive cashback based on how well you drive. Then you drive well and they're supposed to reward you with a cashback based on your qualifying spend at BP. I've been with Discovery since 2017. Since December 2018, my qualifying spend at BP show R 0.00 every month. Then I phone vitalitydrive and the agent at the call centre says that the vitalitydrive card is faulty, even though the card number show on the Discovery receipt. Then I send the receipts to Discovery, usually waits about 2 weeks, then the same automated mail is received from Discovery advising me that the receipts were captured and I'll receive the cashback the following month, which is a month later meaning that Discovery is keeping the cashback a month longer than it was supposed to. Earning more interest etc. on there client's money. Every month it's the same story. Eventually at the end of April 2019, I've asked for a replacement card at Tiger wheel & Tyre, I've used the new card In May 2019 at BP, the Discovery receipt show the new card number. But on my Discovery profile, the qualifying spend shows once again R 0.00. Which means it's the same process all over again and Discovery will keep my money for another month. The error is clearly on Discovery's side. Due to their error, they get to keep their clients money for another month. That's not right. I'm sure I'm not the only client with this issue, If they do this with a 100 or 1000 or 10000 clients, they're earning a good chunk of interest on money that wasn't supposed to be with them in the first place.