I've always paid via Visa Debit but I've just tried my Tesco Visa and it's gone through. I did try it last time and it rejected it.
At least it saves building up a debt. The interest isn't usually that much but we also had to pay for a new meter this time and I wanted to get it paid asap.
Not bad though:
Water for the summer
New Meter fitting
£6.59
Thanks