Unfair late/NSF fee?

[Natalia Collini]

I have a question regarding late/NSF fees. 

I attempted to pay my rent online this month since I wasn't able to get a money order in time to pay the rent. I used their payment portal which only allows transactions directly through your bank account. I linked my savings account that I use specifically for rent money and I received notice that my payment was accepted. Two days ago I got a notice from my bank that that account does not allow that sort of transaction and that the payment would not go through and that we should contact the other party to let them know they would not get their funds. My husband and I went right to the store to get a money order and brought it over to them. Their records still show today that we have paid a full balance for the month, so the NSF hasn't hit yet. Today the Assistant manager called to let us know that we will have to pay the NSF and late fee AFTER it hits on their end and that fee will be $150. This doesn't seem fair to me since we did pay on time and made every effort to get the payment in once we realized the first transaction wouldn't work out. 

On top of this they refuse to fix our dishwasher or our fridge and we have black mold growing in our bathroom, and an apartment that overall is just in really bad shape and falling apart around us. 

Can we refuse to pay the fee? What do we do in this situation? Thanks in advance for any help!