Reminds be of a billing horror story from the states from a few years ago, but I cannot find the link. A man kept getting a invoice from his old power company for a final bill of $0.00 and threatened legal action if he didn't pay it. The letters kept coming with more and more threatening tones.
After many conversations with the power company in question and pleads to stop their accounting system, he eventually cut them a cheque for $0.00 and posted it in and forgot about it.
A few days later he had a frantic call from his bank manager asking why on earth he made a cheque out for such a amount and relayed his story. The bank manager told him that it brought down the whole cheque processing centre for the whole state and caused untold grief.
Anyways, the bills kept coming for $0.00 and he eventually took them to court and ended up having them done for harrassment or something similar, all because of their screwed up accounting system.
Just be glad it has not got that bad yet. You should all ring up Vodafone and ask to make part payments on the bill...
Haha, what a crack up story!