Bonggoy, I know it feels like you're getting ganged up on, but this is a simple problem to solve. Unfortunately, you're going to have to bear the brunt of it, but that's only fair. This shouldn't cost you more than $30-$40 to set straight, yes?
Think of it like this, say you purchased a pair of shoes from one of our UK vendors and wanted to send it back. They would take it, but it would cost you at least what? $30 or $40 to return them to the UK? Would you complain to the vendor that they should pay for you to return the merchandise? No, you would accept that the price of returning the item will be borne by you.
The only difference here is that this seller naively expected everyone to understand the 'unwritten rule'. A mistake to be sure and one he is paying for, however you must take ownership of this situation and find a solution.
The price of returning these shoes is going to cost you something; it has to, as this is your decision to return the shoes. Just agree on a number and be done with it.
I appreciate the response. I bear no ill will against people who responded negatively.
I am working with allaboutshoes on a resolution to something you proposed. We are working on a number that will be agreeable to both of us. This will be resolved.