Of course they can't "force" the person to send the item, but they can certainly can ban her from further listings, unless she has a legitimate reason for this happening. I would love to see her explanation for this one if they got involved. But you really didn't get a very positive response from them. Too bad you got the party line.
I do have my favorite dealers and buy from them, if shipping costs don't make the item more than I would be willing to pay.
I like doing business with another on-line auction site called On-live Auction (ola). As a seller it was great, but because they are small I didn't get very much action. But it is fun to buy from them. Of course, E-Bay is hard to beat for volume of items.