Useless Extra Rewards Programme

I joined the medical insurance since December and pay for the extra rewards which never seem to work! I called and emailed last week, was promised by Venessa that the technical team are working on it and will be sorted out ASAP... low and behold I go onto the website for the Wonda Wednesday special and extra rewards still don't pull through. I get to told I must pay the price that comes up and I will be refunded the excess amount into my extra rewards balance.. Help me understand how this make sense when the whole point is to save upfront and avoiding paying more initially. I pay for extra rewards on a monthly basis only for it not to pull through when a sale is processed. This is upsetting and frustrating because specials differ weekly and what I need now will not be on special when it actually damn start working.