Absolute ******

I have a 100gigs daytime and 100gigs night time data contract with these ******. They however tell me that this month I’m only being given 68 or so gigs for day time usage because I used more than 100 gigs the previous month. How does that even happen on a capped usage contract. I will be reporting them for this, they are going against the contract that I have with them. They have been doing this for as long as I have had this contract without my knowledge.