Taking my money and saying payment failed

Once again - a problem with takealot. Placed an order yesterday on the app. Went on the browser via a desktop pc to complete payment today. Wanted to do a part payment with discovery miles and debit card. Entered all the necessary information, Takealot takes my miles and says payment failed!!!!! I phone in and as usual the consultant can not help despite me emphasising to him that firstly, this is an order for baby formula and Im in a desperate need for it and secondly, this is YOUR fault not mine! HE tells me to go through a long process to get my profile credited with the miles amount that was taken then to replace the order. I really dont have time for this. I am a full time working mother and I really hate that I have to resort to hellopeter every time I need efficient service from takealot. Really this is ridiculous