You are a shopper. You paid YOUR money for an item that you THOUGHT you wanted. By the fault of the seller - either through their lack of thorough description or misleading photos - convinced you that you wanted to buy an item. When you received it, and were displeased with what you bought - you DEFINITELY should just return it.
It is a hassle, but hey - you paid good money for it, right? You should be pleased with your purchase.
I find it absolutely GALLING that someone would beg you to change your feedback, when it was absolutely dead on accurate. You weren't happy with the what you got or how she dealt with it, she deserves the neutral feedback IMO! That's really bad form - to ask someone to change it! Very rude, in my opinion.