Lloyds Bank has been running a new advertising campaign which updates its long-standing black horse corporate branding. The horses no longer thunder along a beach, but interact with people who we assume are actual or potential customers. The soothing payoff slogan goes: ‘Lloyds Bank. By your side.’

The latest episode features a girl who slightly puts me in mind of our 17-year-old daughter. She happens to bank with Lloyds, but there the happy parallel ends. On a Saturday afternoon in March, a person unknown withdrew £440 from our daughter’s account via an ATM. At that precise time, our daughter was playing her clarinet during an audition for a London orchestra.

I see from her bank statements that all her transactions are by debit card, usually for cups of tea or sandwiches, and rarely exceed £5. In the two years since she opened the account, she has not once used her debit card to withdraw cash from an ATM, let alone for such an enormous sum. As everyone knows – apart from Lloyds, apparently – no one under 40 touches cash any more. Yet when person unknown keyed in the demand for £440 of her money, no red flag was raised, no algorithm triggered in the Lloyds computer system.

Her balance was high because of the long hours she worked as a waitress last summer, mixing kale smoothies in our reassuringly overpriced local café. She was understandably devastated when she noticed the rogue withdrawal on her statement, but I reassured her Lloyds would swiftly put it right. Well, I was wrong about that.

It took us some 90 minutes to get through on the Lloyds fraud ‘hotline’, but worse was to follow. There was little sympathy or support from the woman in the call centre. She implied that if Florence had not made the withdrawal herself then she might have given the card and PIN to someone else who did. The money would not be refunded, she said, because there was no evidence that anyone had fraudulently obtained the information to make the transaction. I took over the phone and asked the woman bluntly if she thought my daughter had made the withdrawal herself, to which she replied: ‘Yes.’ I asked to speak to a supervisor but was told Brendan was working from home that night, and unavailable.

In a subsequent telephone call, Lloyds said they would not seek to review the CCTV at the Nationwide branch where the money was stolen, because to do so would breach my daughter’s rights under data protection laws. All they could advise was that we report the case to Action Fraud. This took nearly an hour but won’t help our daughter get her money back, because Action Fraud simply tracks levels of crime and has no investigatory powers.

Banks seem disinclined to address fraud – they would rather defame their customers than repair their useless legacy computer systems. The briefest internet search shows that fraud by cloning bank cards is absurdly easy and common, especially in the era of cashless payment.

Weary of endless waits on the phone, I wrote to the chief executive stressing my concerns not just about the £440, but that my daughter’s credit rating would be wrecked, causing her endless trouble in the years ahead. The woman in the call centre, having suggested our daughter might be a criminal, must presumably have recorded her suspicions on Lloyds’ systems and alerted the credit agencies.

The boss of Lloyds is Charles Nunn, though he prefers to be known as Charlie, according to a corporate video released online celebrating his appointment last year. He mentions that he loves cycling and that after a long career as a management consultant he ‘became very passionate about financial services’ and customer service. Despite these twin passions, he has not acknowledged the letter or addressed my concern over my daughter’s financial future.

Discussing this case with friends, I have found that almost everyone has their own horror story of a family member who has experienced bank fraud. The onus is placed on the victim to explain an event which they did not witness and cannot understand. Then there is a long, dreary road to an appeal to the financial ombudsman once the bank has washed its hands of the case.

Lloyds and NatWest only exist because of the billions taxpayers spent to save them from their own incompetence during the financial crisis. Yet still they close down branches and lay off staff, and act against any objective measure of the public interest. The question is: why do we put up with this outrageous corporate misconduct? Last year Lloyds had to pay a £90 million fine for sending millions of misleading insurance renewal letters to its customers. Five months ago, a senior Lloyds executive was recorded telling staff its computer systems were so outdated as to be no longer ‘fit for purpose’.

Yet Lloyds will not investigate who stole my daughter’s summer earnings. The lesson I have taken from my daughter’s ordeal is that, however much it professes to love horses, Lloyds Bank seems to have contempt for its own customers.