Dress Issue... is this too much? Help!

So, my MOH cousin picked up her dress yesterday along with her daughter's flowergirl dress. They didn't bother to try them on because my cousin's husband is a tailor. Once she got home she tried the dress on and it wouldn't zipper. So she brought it back to the bridal salon and they were able to let out the seams but charged her $75 for this.

So of course my aunt was getting on my mom's case about this (my cousin's used a different salon for their wedding and of course is 'better').

The sister, my other BM, was getting on my case today about it. She is going there today to get her dress and wants to speak to the manager. I said I would meet her there if she wants. But I don't think they are going to waive the $75.

What would you do?

ETA: My cousin was saying to me today how they should have ordered a size bigger and blah blah blah... and how yes her sister might have gained a little weight but not that much so that the dress can't zipper.... and how money is tight and my MOH doesn't have that kind of money to spend. Ugh.. my mom and I have never had a problem with this place EVER.

Honestly most places you go if you are buying the dress there BUT not doing alterations with them they tell you they are not responsible for ANYTHING when you do that. Meaning if its the wrong size they are NOT responsible for that, you are. I know some places WILL measure you place the order and allow you try it on before leaving and ONLY THEN will they be responsible IF its the wrong size.
BUT some places policy is that if you arent doing alterations there, then YOU have to do the measurements yourself and you are responsible for the dress as well.
The store would let you know of their policy though when you ordered them.
And if she gained weight and is admitting that then DEF thats not their fault. And I dont think they are going to waive that $75 and if they are going to a tailor why didnt they just let the tailor take the dress out then why did they do it at the salon?

Yeah, I totally understand... and good point about why they went back to the salon. I guess they thought since it was 'their fault' they should correct it... and for free.

I am going to meet with my cousin at the place later today to make sure things stay cool. I really love this place and would recommend it to anyone. And $75 was the cap for alterations on the contract so.. pfft... whatever. I do think that's a bit high, yes... but... I really don't think they messed up on the dress. I think it was made as the contract said.

Just another issue to deal with. God forbid something might go 100% right, haha.