Adding a Data Cap is a rate change! - XFinity

I was just informed that they will be adding a data cap on my internet account starting Nov 1st. I'm under contract, only 3 months in. How in the world do you not concider a data cap a rate change. I guess in stead of changing my rate they can add a cap and just add an additional rate if I go over a data cap? I'm under contract and my origanl rate should be honored. Adding an additional rate to my rate isn't honoring my origanal rate. I called and tried to turminate my contract since they are not honoring my orig rate and they said I would have to pay early cancelation fees? I did not agree to a data cap anywhere in my contract, isn't that what a contract is for?