Simon Read: 'Fuel bills are getting out of our control as power companies flick the switch on our direct debits'

I wrote earlier this week about the dangers of your energy supplier inflating your direct debit to take account of any underpayments that may have happened during the winter months.

The subject was raised by reader Gary Waldram, who reckons that his supplier, Scottish Power, is actually over-inflating direct debit charges after it raised his by 62 per cent.

"The direct debit increased to £97 from £60, which, considering I only owe £136, is an absurd and astronomical increase," he says. "The increase is even more ludicrous when you consider the winter period is now over, and as I am going into the summer period my consumption will drop dramatically."

I put his story to the company, which told me that the increase in Gary's payment is to clear the outstanding balance on his account by the time of his annual review in July, at which point the payment will be reassessed.

A spokesperson says: "We aim to set direct debit payments accurately. We have recently launched an online direct debit management tool which gives customers the opportunity to manage their own payments. They can increase or decrease monthly payments by up to 20 per cent. If accounts have a credit balance at the time of the annual review, we will pay additional money back."

Gary is unconvinced and warns that other readers may be being overcharged. "High increases are unfair and totally unnecessary considering the amount of data the energy suppliers hold on their customers' gas and electricity consumption," he says.

"If enough people complain, it may force suppliers to improve the algorithms they use to calculate new direct debit payments and allow customers to keep more money in their own bank accounts."

Reader AM Reilly took the advice to heart. "My increase – due on 28 May – was 60 per cent based on a current underpayment of only £34," she reports. "Due to your article, I have negotiated a much lower monthly direct debit adjustment."

Could you be being overcharged by your gas and electricity supplier? Check any increase in your direct debit payments to see whether they reflect your actual usage. If not, my advice is to complain.

Meanwhile another reader, Amanda Willis, writes in to remind us that we don't have to pay by monthly direct debit. "The awful monthly direct debit system, whereby the company can change it as they please, is a complete scam," she says. "You can pay quarterly. You just give in your readings a few days before the bill date, and hey presto, you receive a bill and pay only for what you have used in that quarter.

"You feel much more in control, and it's also easier to have an overview of what's going on with your usage, rather than a payment taken for the same amount every month. I think that people have forgotten that quarterly payments are an option, and the companies certainly don't want to encourage them to remember."

Thanks for the reminder, Amanda. It's certainly an option that could help you keep on top of your bills and ensure you don't end up with a large credit with your supplier.

However, most suppliers do offer discounts to those paying by monthly direct debit – or penalise those who don't – so there's that extra expense to bear in mind.