Comcast False billing balances, Internet

Checked online for billing balance, it showed 20.95 due.  I was even sent a bill for 20.95 by mail.  SO I paid it on the 9th of January.  I checked to make sure there wasn't any other bills, I even called and had my service changed a little (I wanted to drop my phone and instead they dropped the price 30.00 for 6 months) while speaking to the lady, she checked the balance and said I was up to date.  I got a bill from comcast on January 19th, 10 days later- for $248.00!!!! wth???

I called right away and got this for an answer: Well, you call when you bill is too much, you should have called when your bill was 20.95!!! Absolutely the truth!!!  AND they said the balance went back 2 MONTHS.  Meanwhile they are adding late charges.  There was absolutely no compensation only pay the bill or we shut it off.  I would certainly like this matter taken care of.  I guess my next step is local tv, there is a "On your side edition" there.