Unhappy customer

I received an email earlier about a burger special from KFC buy 1 get 1 free and I placed an order of 3 burgers thinking I will receive 6 since I used the promo code they gave me but I only received 3 and I called to find out what went wrong the lady said she will check my order and get back to me but I'm still waiting I feel like they do false advertising so that we can use they're services