I know what you are talking about, I know that some stores will "try to" refuse returns on some higher price items because that transaction will resulted in a "negative" sales and that store has to "eat" the return stock. All that means: stores take the return usually ended up losing money because they have to write off that return or sell at further discount price (since they make too little margin on anything).
If this happen, you can always fight your way through because they cannot do that at all.
At my work, some stores are doing this... and if I know that they are refusing the return, I will transfer that return back to the stores.. :-D
Philip |