AT&T stole my 50 dollar reward!!!!

I opened an internet account and the promotion shows I can get 50 dollars rewards. I was never told how soon I can get the reward. Then half year passed, I still never got the reward. Then I did an online chat with AT&T. Samuel talked to me and provided a phone number of reward center. Then I called them. First time a lady told me that she would transfer me to customer service. However, she transfer me to the reward center again. I waited 20 minutes for the next available representative, then Maria talked to me and after a lot of questions of address, password, account number,etc, she told me she would transfer me to customer service. I asked her at least 3 times I want to be transferred directly to customer service. She said yes and then I was transferred to Directv!!! Interesting! I called the reward center again then Maria again answered the phone. I said I need to talk to her supervisor. The supervisor did not say sorry to me but repeat the statement then I finally was transferred to customer service. 1 hour and half passed. Gimmel answered my phone and told me my reward has expired and I cannot get any reward at all. Oh my god! I have not received any message or email or mail about the reward, then it is stolen by AT&T. I told him I need to talk to his supervisor. He asked my phone number and told me someone will call me in 30 minutes. 16 hours passed, nobody call me at all. 

I wonder have you guys met this situation? I do not know why the people in the customer service qualified for the job. Also, I suspect that they are allowed to do this to waste my time and then maybe I will not call for the reward. Yep, ON PURPOSE!!! 

AT&T may have the worst customer service in United States! How do you think about it?