A Kent woman who has invited a Ukrainian family of refugees into her home was told by John Lewis Home Insurance that she had to pay an extra £41 a year as a result.

Despite promises by the Association of British Insurers that people would not be penalised for taking in those fleeing the Ukrainian war, John Lewis demanded an extra £41.74 from Cath Bateman, on top of the £381 it recently charged to renew her home insurance.

Bateman, who lives in a terrace house in Dartford, decided to offer the Ukrainian family somewhere to stay after learning that they were crammed into a small house.

The family – a mother, her daughter aged 12 and four-year-old son – had been rescued from Poland by the mother’s sister, who is originally from Ukraine but now lives in the UK.

After the Guardian raised her case with the company, John Lewis said a mistake had been made, and that Bateman would be refunded.

“I don’t have a big house but had two free rooms and offered to put them up when I learned that they were having to sleep on the floor,” said the retired teacher.

“I thought I had better tell my insurer – more out of courtesy than anything – but couldn’t believe it when they called me back to say that I would have to pay an extra £41. It feels completely wrong.”

At the start of the conflict the Association of British Insurers said the industry stood “united with the people of Ukraine in the face of the Russian invasion” and that people housing refugees would not face financial penalty.

“If you are a homeowner in the UK and want to temporarily house refugees who have been displaced from the conflict in Ukraine as non-paying guests in your home, you do not need to inform your insurer and your cover will remain the same,” it said.

“This applies for the first 12 months of any refugees living with you, including when your policy is due for renewal. After 12 months, if any refugees are still living with you, then you should tell your insurer when you next renew your policy.”

A spokesperson for John Lewis said: “We aren’t charging any additional premiums for our customers who are welcoming Ukrainian refugees into their homes. We’re very sorry a mistake was made in this case and the customer will receive a full refund.”

This was just one issue faced by Bateman. She has been told that because the family were brought into the UK on a family visa by the sister, she will not be able to claim the £350 a month payments the government has offered. She has also been told that she has to get a £95 gas boiler safety certificate at her own expense.

“I’m still really pleased I have done it, and we are getting on well. However, the authorities could certainly do more to make it easier. Why those who help people who are brought in on family visas are not entitled to the £350 payments is beyond me. All our attempts to address this have so far failed.”