How can I actually cancel my services after continuous lies from customer support

I have been trying to change my services as other companies are offering higher services for much less. I spoke to an agent last week, was promised a lot of changes and savings and after the changes went in, hardly anything stated was true. After 7 hours yesterday of being on chat after chat being bounced around from agent to agent I have even less services and not what I was told i was going to be paying. After being a loyal customer for over 11 years when I try to cancel my services I get offered a higher package that costs more than any of the plans I was offered in the past week. How does this make sense? New customers get all the perks while loyal customers get lies and extra charges. Over the past few years we have lost numerous channels including the regional sports channels that we were charged for but stuck around hoping things would get better. I have the transcripts saved and even made up order confirmation numbers, how is that even legal? When asking about it, no one can give me an honest answer.