Pizza Hut, you have to keep your word

For the last 3 orders of Pizza Hut food, I have completed the survey (shown in red box) and instead of giving me a "code" for the free small size pizza (to qualify one must also order at least one item from the menu) Pizza Hut informed me they will email me the code for the free pizza. After waiting for almost a month or so, I have not recieved the code.
Prior to December 2014, Pizza Hut would immediately give me the code for the free pizza once I've completed the survey instead of informing me they will email me.
However, I will still patronise Pizza Hut because the food and service is very good,regardless of whether they will give me the free pizzas or not.