Lucky you! Here (Australia) a common ploy by ISPs offering high-speed low-cost is to limit the total download GB, and then throttle the speed down rather than cut the service completely, so that they can still call it unlimited.
My parents are on a $30 per month plan that is intended as a phone-replacement service. Includes phone number, cable, device and 10 GB data per month which is enough to cover 200 hours of phone calls. I thought it'd also be enough to cover mum's sudoku games on her iPad, but we got stung by iOS updates chewing up 3 GB each try. When the 10 GB cap is hit, speed reduces to 32 kbps, which makes the phone service barely intelligible. Yes, I have complained to the ISP about this: if they upped the capped speed to 64 kbps or didn't cap VOIP packets, then we'd be sweet.
Happily, the iPad takes a SIM, so currently we're paying an extra $10 per month for that, which has the benefit of the iPad still working when they take it on holidays anywhere in Australia (well, anywhere within the 97% population coverage area, anyway) (including around and on top of Ayers Rock a couple of years ago).