aren't typically returnable, simply because they are no longer the "stock size" they were when they were manufactured.

But I have to wonder how you had custom alterations done to your suite and never tried it on before a major event. My fiance had 2 suits he bought and had altered before a formal event at my work last year. He picked them up on a Thursday morning and tried them both on as soon as he got back home, just in case he needed to have further alterations.

That you waited until the day of the wedding to find out the suit didn't fit, forcing the purchase of yet another suit is also not their fault.

I don't believe that the intention was to "treat you like a criminal" but they told you NO and for whatever reason, you believed that translated to poor customer service. It's not - it's pure common sense. You can't custom alter clothing and demand they take it back if the alterations aren't sufficient. They just need to alter it again and you might have to invest a little more time in the future.