Atrocious service and short delivery

I placed an order on the 29th of June on the kfc app and the store was Kfc in West Street Durban. I received a short order on top of that the delivery guy was rude and agressive. I have complained and Kfc has done nothing about it instead they keep sending me Sms's to call them. Why should I spend more of my money when I was the one who received atrocious service from a bunch of *******