There are some serious questions that need asking about why interest rates are not fixed.
We heard for a long time how when rates were low it was a great time to borrow money. Well that was the time to borrow long term on fixed rates. Why did the treasury massively underestimate the increase in costs? I have no idea what rules there are around interest rate management in government but I work in a bank and when this sort of thing happens its generally because someone fucked up and was not following policy.