COMPLAINT!!!!!!

I always order food from KFC online and pay with the card, but on more than 1 instance, the app shows the food as delivered without receiving the food. Every time I call customer care they just throw me with a voucher and disregards the inconvenience caused. It has become such an issue and I decided to formally complain today and guess what?? I was given 3 vouchers to the value of my purchase. I was informed that I may only use 1 voucher per purchase, how I am suppose to order my food again if for the same purchase I can only use 1 for. I order 4 meals, and I am expected for use 1 voucher per order. Lebohang Molefe from customer care was not very helpful and I am still waiting for a manager to call .