They are deducting money from the trust fund

My daughter lost her grandmother December 2020, her Trust moved from her gran's company to Fairheads. I was told that the money I will be getting on a monthly basis for my daughter wouldn't affect the Trust fund, I will only be getting the interest from the capital, the only time it would change would be when I claim from it.

I have not claimed for anything from April 2021 to date so which means my daughter's capital (Trust Fund) should still be the same amount. I just learnt that they are actually deducting the money they send on a monthly basis from the capital amount and my daughter is only 9 so by the time she is 18 she won't get anything at this rate. They shouldn't be deducting from that money because they are sending the interest.