Our 16-year-old son has an incurable degenerative disease and now needs round-the-clock care. My husband has had to give up work to look after him but Aviva is refusing to pay out under our critical illness policy.

We’ve been paying £60 a month for the cover since 2007.

Our son was born in 2008 and diagnosed with spinal muscular atrophy with respiratory distress (SMA-RD) when he was eight.

He managed well in mainstream school until June last year, since when his health has deteriorated significantly and he has paralysis in all four limbs.

We contacted Aviva in January to discuss our eligibility for a claim. We were transferred between three departments and waited more than three-and-a-half hours. An adviser repeatedly stated that he did not meet the criteria, but would not tell us what the criteria were.

We twice requested copies of our policy documents, but they were never received. We raised a formal complaint about their communications in February and our consultant submitted medical reports.

In late June, our claim was denied. Its argument is that SMA-RD is a genetic condition that would have been present at birth, while his cover on our policy only started on his first birthday.

I suppose that is why Aviva has reported £1bn operating profit in the first half of this year.

NL, Belfast

Insurers look upon human suffering through the lens of terms and conditions, and cold hard cash. It has to be this way – they are businesses. But commerce does not preclude compassion and this was shamefully lacking in Aviva’s dealings with you.

Despite the urgency of your circumstances, it took five months to reach a decision. The email trail you sent me shows your repeated pleadings for updates.

Your critical illness policy automatically covers children once they reach their first birthday. The terms and conditions do, indeed, state that illnesses that are present from birth are not covered and that symptoms must not have started when the cover begins.

You sought advice when your son was one as he wasn’t meeting certain developmental targets, but all the tests came back negative. It took another seven years before he was diagnosed with SMA-RD.

The Financial Ombudsman Service states that it usually upholds complaints about claims rejected because of pre-existing conditions of which the customer was unaware.

It also says that it overrides exclusions in insurers’ terms and conditions if the customer had only general symptoms when cover began, and could not reasonably have foreseen that they would later give rise to a claim.

There are many reasons why a one-year-old may miss generalised development milestones and most aren’t incurable diseases. I therefore put it to Aviva that you could have had no way of knowing that your infant son had a serious condition that would lead to a claim 15 years later. I suggested that, given the complexities and the timescales, it was rejecting the claim unreasonably on a technicality.

I was startled by the speed of Aviva’s response. Within two days it had told you that, although it considered your claim had failed to meet its terms and conditions, it would pay you the full £10,000 allowed by your policy. It freely acknowledged that its about-turn had been prompted by my intervention. The money was in your account a few hours later.

It says: “We fully acknowledge that our service and communication did not meet the standards our customers rightly expect from us. The family’s situation should have prompted a more urgent and compassionate response.

“While we are unable to approve NL’s son’s claim because of the terms of the policy, we recognise the unique circumstances of this case and the shortfalls in our service, and believe that it is appropriate to make a goodwill payment that is equivalent to the benefit the family would have received had the claim been eligible.”

Coming up to scratch

Most companies get it right most of the time. Most put it right when they don’t. And some exceed expectations so magnificently they deserve a shout-out.

“I have a £73 pair of Cocoons sunglasses that fit over ordinary glasses,” writes LR of Colchester. “I have macular degeneration and UV protection helps slow this. My puppy got hold of them and scratched the lenses. I rang the company to ask if this would damage the UV protection, and was told that, under the terms of the warranty, I could get a new pair by paying £2.99 for postage.

“I said that I did not think that a four-month-old German shepherd counted as ‘normal wear and tear’, but a new pair duly arrived.”

We welcome letters but cannot answer individually. Email us at consumer.champions@theguardian.com or write to Consumer Champions, Money, the Guardian, 90 York Way, London N1 9GU. Please include a daytime phone number. Submission and publication of all letters is subject to our terms and conditions.