This is spooky!!
I switched over to water meters nearly 18 months ago (i live alone, so cheaper) and Severn Trent were very good about it, came out promptly did the work well and even fitted a brand new stopcock at no cost (they say they charge for this).
What happened is they cancelled my direct debit and opened up 2 new accounts in my name (i have 2 meters as i have 2 incoming water sources), this is fair enough but they didn't set up new DD's.
They didn't even bill me though.
Sooooooo, about a month ago i get a red letter saying they are taking me to court unless the outstanding amount is not paid in a week (i got 2 letters of course).
Here is where i disagree with you Greg.........average waiting time!!
16 minutes!! YOU ARE HAVING A LAUGH

I gave up twice on 30 minutes and on my 3rd (and final) attempt they answered after 21 minutes then transferred me to a different department where i waited for ANOTHER 20 minutes or so!!
They could not find my account(s) or any record of me at all and promised to call me back the next day after some investigating, i asked for a direct line but they wouldn't give it.
Needless to say they haven't called back........
Interestingly i have been told that water is the only utility that CANNOT be cut off for non payment

So SOD 'EM i say.
BTW if anyone is thinking about water meters i live alone in a 3 bedroom house and they want around £50 for the last 18 months, now that is a saving (if i were to pay it)