Need help. Can't find anyone to help me. I was promised 2 years at a certain price for internet/TV

Back in Feb, 2019, I was promised a certain price for 2 years. I didn't ask for it. It was offered to me. I have it in writing along with a confirmation of the order. I have chat sessions to confirm this. Now my price has increased a good bit but ATT is telling me so sorry but nothing they can do because no promotions to put on my acct and promos have fallen off. It has only been 6 months. Why confirm a set price when my cost will keep jumping up during the 2 years. I don't get it.

Why did AT&T employees promise me 2 years at the same price (and I confirmed this with them over and over and they confirmed back) and now they say they have no choice but to increase my price even though it was promised to me at a certain price and confirmed? 

Chat was of no help after working with them over 2 hours. All they said was that they were sorry but nothing they could do. I'm so angry right now. I just want to know a person that can help so I don't have to spend all day on this. Either someone can help me or else I have no choice but to leave ATT. I have always bragged about ATT but this is not acceptable and I will just simply go elsewhere or cut the cord.....not that ATT cares...evidently they hear this everyday so they are numb to it.

Thanks in advance to anyone that can lead me in the right direction. I did a chat and was transferred to 3 different people and just tired of explaining this over and over. Just give me a person that will help and not transfer me to someone else over and over.