one roof one bill !

i live in a row of flats and it really anoys me that united utilities get away with billing all 62 flats for waist water that runs of our roof etc. my yearly bills for water are around £50 but after they add on the charges it comes to around £300 for the year and if you times that by 62 its £18600 ! we only have the one roof so its not fair that they bill us all for 62 roofs. i have said for years the bill should be devided not multiplied so please please sign my petition and lets stop one of the big companies ripping us off !!!!