Simon Read: 'Big companies show they can, eventually, do the right thing'

I've spent much of the week dealing with your questions about problems with big companies. Reader Michael Green reported that when he switched his energy supplier last year, he received a final statement from npower showing that he was £518.69 in credit.

Great news, you'd think. But energy companies are notorious at keeping hold of people's cash after they leave. In fact a survey from uSwitch this week suggests that up to £235m of our money is lying around in closed energy accounts.

Back to Michael's £519. He phoned the company in December to be told the cash would be in his account within 28 days. It wasn't. He phoned again in February, to be promised that the money would be paid into his account within 10 working days. It wasn't.

Understandably exasperated, he contacted me. "I feel like I've been punished for leaving npower," he said.

I took up his case with the energy giant and, thankfully, it responded quickly. In a statement, npower said: "We're really sorry to hear about Michael's query and the delay arranging a refund. We're refunding the credit as a priority and we've also factored in a suitable goodwill gesture to apologise."

In fact, it isn't only making the refund a priority but has increased the total credit to £600. That's good news, but still doesn't excuse the poor service in the first place. However, the company did at least react positively when I challenged it.

As did Prudential when I followed up a reader's complaint that she had been needlessly paying premiums for a home insurance policy she didn't need, but couldn't get the cash back from the insurer. To be fair, Prudential had told her that it couldn't cancel the policy as it was in her ex-husband's name and she needed to cancel the direct debits – which she failed to do. That's why the premium payments kept on leaving her account.

But then again she had been going through some tough times, including a divorce and the death of her father, so she had failed to keep a regular check on her finances – or look at her bank statement. As a result, six years had passed before she realised the rogue payments were still being made.

When she did, she had trouble getting the insurer to sort things out, so she contacted me. After my intervention, Prudential saw sense. A spokesman told me: "Unfortunately, due to data protection laws, we were unable to cancel the policy in her husband's name without his authorisation. But we should have been more proactive to resolve the matter sooner."

It has refunded £2,568.21 in premiums, as well as handing over £200 compensation for the distress. But the key lesson is to check your bank statement. As hundreds who contacted me about BT's unexpected "caller display" charge discovered, there could be all sorts of expensive mistakes there.

s.read@independent.co.uk

twitter: @simonnread