KFC- Terrible customer services

Good Day.

I bought 10 zinger wings at KFC mayfair and when I got home, I was only given a 2piece chicken. I then went onto Twitter to log a complaint and they confirmed someone will call me. They did call and apologize for the error and asked that I come back to the store to collect my wings, to which I responded I was only in the area for some shopping on a random Saturday and who is going to fit the petrol billing can they not rather give me a voucher to go to any KFC that will be near me. It has been now1 month and 2 weeks since this happened, and I am yet to be contacted. I seriously do not understand how such a big franshise cannot just provide me with a voucher for an error on their side.