Made assumption to ensure bonus paid back

Outsurance paid the Out-bonus to my mother on +-20th May. My father died end of March and my mother now pays all the bills. She noticed that the water bill was high in April but assumed that this was due to all the washing she was doing, washing all my fathers sheets etc. When the bill arrived in June and the water bill was still high seh suspected a problem, she asked the neighbor around 15th June to come and have a look as she thought the geyzer or the irrigation may be causing the problem, The neighbor had a look and found the water meter was running with no taps open. My mother called out the irrigation people who confirmed no problem there. Then On around 20th June my mother called outsurance to open an incident. A outsurance plummer came out and discovered a leak in the wall, At this point she was advised that as she was aware of the leak in May she must pay the bonus back or the leak would not be fixed. I have asked for a transcript of the conversation but never received one. Called outsurance just before 5pm and was cut off, obviously home time. How do I get clarity on this, must I go to the ombutsman?