Data Cap

I am currently using xfinity  in Florida as my internet provider. I am using one of the 1.2 TB data cap plans. On recent months I have been going over the cap. We are a household of 5 people and everyone is usually online doing something. So in my view the 1.2 TB is not enough for a family with so many internet users. Besides that,  I have reached out to xfinity to find out how I can remove the data cap and go to an unlimited plan. The employee at the store told me if I pay $10 extra a month, I could remove the data cap but for me to do that I had to call a phone number and ask for the promotion. I called the number and they told me that I had to rent their equipment to be able to have that promotion and that I could not do it if I own my equipment, which is the case. I spent a lot of money on my own modem and router, and I think this is unfair and a way for xfinity to make more money. I believe I pay enough for internet usage and I should not be banished from promotions just because I own my own equipment. Another point is that 1.2 TB cap was probably good 4 years ago, but today, everything you buy has a connection to the internet and it probably does not apply today. That cap should be double for today standards.