Promotion price not applied

Hi,

I am a cox internet customer. recently I purchased Cox TV after seeing the online Promotion price of $29.99 for first 4 month with free professional installation and free HD Receiver, I contacted customer service representative who confirmed me that I am eligible for this promotion offer.

I was expecting my monthly bill = $19.99 (internet) + $ 29.99 (Tv) = $49.98. 

but when I received my first bill, I was almost shocked. it was $182

This is really weird, and it was a bad experience for a new customer like me.