comcast cable tv over charge me and no explanations pay or loose service they are a fraud hialeah, Florida

november we decided to up grade system and install tv also  we had internet and 2 telephone lines  they cam on november 9th to install they know off my phones left us with no telephone for 4 days after all the fighting back and forth and after 4 techs came to house to fix what they mess up from main office they accepted their fault gave us credits and free hbo for 1 year and all works fine for one day my tv frooze  after 2 techs came to house they accepted to replace main box a tech came to hous 4 days later because they have no one to come i when to office and they line was to milles long i called internet line they send me a box and still not install till today 12/29/2011 i checked my bill and from 88 dollars i was paying in november now my bill is 400 dollars all credits became charges and service still not completed and to top off my november bill is charging me installation 3 times 50 dollars same day november 11 2011 they are a rip of  the nice part is that i have printed out papers from such days with all the credits and charges now all this is gone and they posted what they want they told me they have no credits on the system at all i told them i had papers from their data base and they hanged up the phone i call them back and ask for manager to call me back to fix this or was going civil and still waiting for  their call and my system still not working