Discovery Insure - car insurance

I signed up for Discovery Insure in August - being told that I would receive a monthly cashback award for (a) fuel spend and (b) good driving behaviour. For September month I received a FUEL cash back as well as cash back for DRIVING well. For the month of October, I received a fuel cash back ONLY despite my driving behaviour remaining on GOLD status! You are told to (1) fill up with petrol to get money back and (2) to drive less to be given additional points. So, you fill up your tank but then you need to drive less - so what is the point of filling up your tank but then you must limit your travelling! I would have stayed with my previous Insurance Company had I known that the Discover "rewards" are just a ploy to get you signed up as a customer. So - what is the point of driving well / filling your tank with petrol ???