OK, this is what happened:
1. I paid in several cheques to my account - say total £2,000 on 1/7/12. They were not due to clear until 5/7/12.
2. One cheque for £900 bounced on 4/7/12 and the bank immediately took the money from my account.
Now they are charging me interest for one day as this apparently made me overdrawn.
They claim that this is correct. It sounds fraudulent to me. As a "gesture of goodwill", they have agreed not to charge the interest "on this occasion"
Can this possibly be correct?