75% cash back is a lie

On my app it shows that I will earn 75% discount on Woolworth purchases. But when you take the spend limits into account and the fact that you only get 25% from Discovery health and 50% from bank the net effect comes to a total of 37%. This is false advertising. In an example, if I get 25% back from a R2000.00 on health it means I got back R500 back. Then if I get 50% back from card on a R2000 spend, I got a R1000 back. Add the two together I got back R1500 back from R4000 spend. That equates to 37% and not 75%. I am being **** to by Discovery vitality and their apps.