healthy foods cash back july and August

Good Day

I have a few complaints, and I'm really frustrated that I've been calling and getting query numbers but up until today my issue is not resolved.

firstly July 2020 my vitality cash back was 50%. On the 17th July 2020 i received R980 cash back from vitality, because every month i used to get my cash back on the 17th of each month.

August 2020 i didn't receive any cash back because you guys send out notifications that we will get paid out from the second week in September, when September arrived i only received R289 (calculations was on 15% and not 50%)

my question to you is why didn't i get my remainder cash back of July and why did i get cash back on 15% for my august spend when my cash back calculations for august month was 50%?