If you entrust an intermediary to handle the loan, it should be considered reasonable for the intermediary to charge a certain amount of remuneration, because the intermediary also has to eat and develop. If you think the charge is too high, you can not find this one, or go directly to the bank. In short, as long as others serve you, you should charge a reasonable reward. Of course, if the remuneration is too high or exceeds the agreed remuneration, you need a reasonable reason, otherwise you can refuse to pay. The so-called "obligation" actually has a price, but you may not realize it.