I'm not really sure about mp3 players, but are you sure that it actually only holds 245mb, try and put a 300mb file or something on it because it's true amount of space migh be 512, but the format area may say 245. (Not sure if that will work or not, just have a go)
If not, then I'd take it back to save any hassle, it is basically brand new, so you may aswell .
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