Billed for old phone calls

[#1]

Hi,
Just looking over previous home phone useage and looks like the system didn't bill me from November 2010 through to Jan/Feb 2011 and then gave me one big bill in Feb 2011.
Does anyone have an idea as to why this may have happened?
Thanks,
Brad

[#2]

Hi bradsalmon,
it looks like there was a billing issue I'm afraid. I cans see that you were charged line rental from November but not for calls. It does appear to be our fault so apologies for that and the fact that it wasn't communicated to you at the time.