My property agent will waive a charge if we pay prompt?

If you agreed to the arrangement fee in the contract, you are obliged to pay it. The time for asking what you were agreeing to was before you signed the contract. However. If it isn't in the contract, they can swing for it.

By all means dispute the cleaning - get the deposit scheme to arbitrate, they are usually fair.

First off, decide what you think is fair for her to keep (maybe $20, just to get this done - even if you think her deserves nothing). Then say she can keep that and yo won't sue her for the rest.

If she refuses this offer I'd ask her to take whatever you owe out of the deposit and return it to you. Since she gets the $$$ immediately you should get the $30 off. Tell her you also want a full accounting of where the money went but that you feel this is unreasonable and you might take it to court. I think that if you pay her then its as if you are agreeing to the charges and therefore you have a weaker position in court (probably why she wants you to pay her) so I wouldn't do it - make her take it out of the deposit and refuse to sign anything stating you agree with this.

If she keeps the extra $30 or even if she doesn't but you still think this is unreasonable then take her to court. Though there is a chance you could lose in court I wouldn't pay her anything (make her take it out of the deposit) just on principal unless you are ok giving up the $90 for the cleaning.

Ive never heard of an arrangement fee... what the heck is that supposed to be for

If you are disputing the charges for anything you need to be able to show that there was nothing to charge for. Did you do a pre and post walk though with your landllord and document everything wrong when you moved in and out.

You will have been given the details of challenging any deductions when you were issued with the TDS documentation. If you can afford the inevitable delay in returning the money then register your challenge with the TDS.