But its telling me that I don't have myt curtesy month now and I have to pay an extra $10?
You have been charged $10.00 for the additional data provided over your data usage plan
July 1st the courtesy month was dropped from 2 to 1. Even if you had one month left of the two courtesy months between January 1 and June 3, it dropped off, and everything started new July 1st.
Apologies for the issue and the experience that you described above.
There is now only one courtesy month and the monthly usage has been increased to 1.2 TB.
Details here: https://www.xfinity.com/support/articles/data-usage-what-is-the-terabyte-data-usage-plan
As a courtesy, I have credited your account $10. Thanks for your patience.