Thanks for sharing your data usage concerns with us! I can understand why this would appear confusing. Just to clarify, every Rogers Infinite plan will include a specific amount of high speed data. Once a customer has reached their limit for their data bucket, they'll still have access to unlimited data, however, it will only be available at a reduced speed of 512kbps.
This reduced speed still allows for many everyday activities such as basic email, browsing, texting & apps. Customers can also buy a Speed Pass for more data at high speeds if required.
I'm noticing that in your screenshot of your wireless plan services, it shows that you have a "Share Everything plan" and not an Infinite plan. Perhaps I am missing something?