BILLING doesn't match CONTRACT

Hello, I have been with COMCAST for 10yrs and now that I was eligible for a new contract since I've moved my business and my new contract was going to be around the same as what my previous bills have been, up until that new contract... I have been under what i thought was a great new contract since November 2015, almost every month I have had to call and argue my charges... I thought a contract was a binding document???? I guess when it's in Comcast favor it is not binding!!!  Totally unfair, I shouldn't have to call every month and don't have that much time to spend on the phone, also the inconvience makes the situation harder to deal with so I do feel bad for the poor souls in the billing department since they are not really the ones that are causing the problems, I have to say they do try thier best to help.  I also shouldn't have to be on the phone for an estimated 2hrs trying to fix a bill that is supposed to be one $$$ amount every month.  Then causes me to turn off and on my auto pay.  I understand fees go up, but a CONTRACT IS A CONTRACT.  My bill is not supposed to be $12.00 or $$ more a month, COMCAST YOU NEED TO ABIDE BY YOUR CONTRACTS we as customers would pay a fee if we didn't abide by the contract.   I've been over charged from day 1, I believe it's made more confusion.  COMCAST I feel you owe me at least 1 to 2 months free service with all the over billing and charges I've incurred in YOUR BINDING COMCAST CONTRACT.  Thank you a small business owner