Direct debit payments are convenient for both the suppliers of utilities and their customers. The former are guaranteed getting the money in and the latter, through paying a set amount monthly, are able to avoid those nasty moments when a big bill arrives and there isn't the cash available to pay it.

The utility companies are always keen to encourage their customers to use a direct debit arrangement, and when the system works correctly both sides benefit. Unfortunately there seem to have been far too many instances lately when the system has failed - and not to the customers' advantage.

The scores of Bradford householders who have been left waiting months for the refunds on their annual electricity bills generated by over-payment on direct debits have every right to feel angry. They have played the game and are being penalised as a result of their annual consumption being over-estimated and their monthly payments being too high.

When they end the financial year significantly in credit, they should be given their refund promptly. These days people have too many demands on their funds to have cash tied up wrongly and unnecessarily.

A statement from the Energy Retailers' Association, which includes npower, denies any suggestion that companies are wilfully holding on to customers' money. Be that as it may, scores of customers who haven't received their refunds have had to turn to Energywatch North East for help in getting their money back.

If the delays are caused by incompetence, npower needs to get its act together before customers decide that the convenience of paying by direct debit simply isn't worth the trouble it causes.