I always check my online account daily to make sure I'm ok to pay bills etc..
I checked it yesterday and saw that when I used a paypoint to pay my Southern Electric gas bill it'd come out twice
I went into the shop and they went through everything but couldn't find any evidence it was their fault. So today I rang Southern and they eventually found it'd come out twice and said it was the bank's fault?
They're now sending me a cheque so I'll have to wait for that to arrive, go into town and then wait for it to clear.
I rang Lloyds TSB and they were very matter of fact about it saying 'oh well at least it's sorted now'.