Rewards card ripoff

I was supposed to receive a rewards card of 150 for signing up for a U-verse bundle in late september 2014. I was told I would recieve an email at a some point to activate reward.  i never received it.  I did not receive an email or snail mail.  My wife has been in the hospital with a broken neck.  I finally realized I did not receive any notification so I called customer service.  They transferred my to the rewards center. They told my the offer expired.  I never received any notification on how to claim the reward and att will not do anything for me.  I keep calling and getting transferred back and forth between customer service and rewards center and no one will help.  They just say it is expired, too bad.  I ask to elevate but they say the manager is not there or no one has authority to do anything about it.  I feel like i was ripped off to the tune of 150.  I wanted to cancel but that would cost me 360!  Very frustrated.  I could not recommend att to anyone.