comacast comcast cable billing problems over charges pompano beach, Florida

I received a bill tonight when I got home, for almost 3 months of internet and phone charges, I went on line on the 24th of october  and I had a 0 balance because I wanted to pay my bill, I did not htink other wise then when I received my bill it showed that  on 09/25/12 it had  a negative payment of -76.62 eft reversal then on 10/04/2012 a eft payment of -76.62 .. I called the 1-800- number they where closed I went on line and typed in all my payments I paid on 09/25/2012 and then 10/04/2012  now they said I had a bank over draft that is not right I paid on line and it gave my a confirmation on both payments, now the bill shows I have a late fee of 8.00 and a 30.00 return check fee on 10/02/2012 ... and they want me to pay 196.30  this is absurd the person I was typing too said I need to call the bank because it is there problem and mine not comcast after I told him when I went on line on the 24th of october 7 days a go it said I had a 0 balance,, I went on line because I am on social security and pay all my bills when I receive my check... this happens like every 6 months and finally I am tired of comcast trying to rip me off again.