reactivation fee!

I check my Internet bill on the first of every month, unless it says I have a credit the month before. (Sometime I prepay a month or so in advance) July, it said I had a credit and this month... September, it said I owed a reactivation fee of 24 bucks! That's close to half my bill! 

I went through all my bills again with a fine tooth comb only to see that they take the money from the credit on the 19th, so me checking on the first was pointless!