It’s a risk reward analysis and not strictly a 1:1 hour pay relation. No one guarantees you any positive outcome here.

Best case I get the fee removed after a short conversation.

Worst case, I have to engage in a long drawn argument still having to pay full afterwards.

best case was a simple mistake and I just have to ask politely. This can be considered very unlikely in this case because the recipient has a dedicated section for the fee, indicating that they’re not going to make any change to the bill. So the risk reward is highly leaning towards the worst case as the expected outcome.