Comcast cable company — overcharges

I signed up fpr comcast triple play and was told my monthly bill woud be $119.00 per month plus taxes.
However, every bill that comes has been higher and when I call they keep saying that the next month it will be straightened out but it never is and I keep getting higher bills. I dred getting their bills in the mail because I know that I will have to get back on the phone about the same problem . I just want the price that was promised and be left alone for the year agreement..