VISA PRE-PAID AND MBPS

I signed up for a bundle deal. TV, Internet, and Homelife. I was offered a 250 dollar visa prepaid. Come to find out this was NOT true at all. I am only being offered 150 and of course they don't have document to back it up besides the 150 showing on their end. I need to know how to get out of my contract for not holding up their promise. Also, my internet speed states its 150 mbps. I have never seen my download speed anywhere near that. I held my end be paying 3 months without a late payment and this seems ridiculous. This is one of the main reasons why I don't like cable companies. Any bit they can get out of you they will and when you question it they offer you some random deal or drop in payment, but the fact is your problem is still there.