I too am having the exact same problem. I have never come close to "going over" and now the past 2 months I have exceeded. I too am being told to purchase an addl $25 of protection for this! I too am not getting any real answers from Comcast. I need to know who to contact to get the real story. I am almost a 1/3 used up for this month already and it's only the 6th?