I am thinking of switching to other ISP from telecom.
The billing period for my homephone is 01/08/2010 to 31/08/2010, and my broadband's billing period is 09/08/2010 to 09/09/2010.
Say if I want to make the switch next week, and it will be either the 4th or the 5th of August, what is my bill going to be like?

Will they charge me for the days I used or
will they charge me for the whole month I haven't used for my homeline?

thanks